SkyZero Podcast

So I think that, you know, electric aircraft, you know, when they're on the market, like the S30, they're going to win for the routes that they're capable of flying. Right. And then as the technology improves, you know, eventually you'll get to the place where you can... You can say, okay, for these short flights, we can be all electric. We can remove the turbine system. We can make the aircraft a little bit cheaper by doing that. But you're also going to be pushing into those longer flights at the same time and saying, okay, now we can do 300 -mile flights with a hybrid aircraft. Now we can do 400 -mile flights with a hybrid aircraft. Right. So let hybrids be the pioneer and battery -only can sort of come along behind it. Yeah. That's how I see it. I think that when the technology gets to that point, the short flights, electric only, that's going to be the way that we really lower the cost of flying as much as we possibly can. And then the hybrids, you will realize cost savings with the hybrid system as well relative to a fully conventional aircraft. And we'll just keep pushing that up to get the most range that we can. Ben Stabler is the CTO at Hart Aerospace, a Los Angeles -based startup developing a hybrid battery electric regional aircraft. Prior to joining Heart, Ben was co -founder at Parallel Systems, a startup building battery electric rail vehicles for freight transportation, and spent five years at SpaceX designing power systems for the Crew Dragon aircraft and leading the avionics software team. Ben is also the guest on today's episode of the Sky Zero podcast. Ben, yeah, thank you so much for joining us today. I really appreciate you coming on. Yeah, thank you. Excited to be here. Yeah, for sure. Me too. So I wanted to sort of start with, like, about you, you know, and how you got into all of this. We heard a little bit about your bio just now, but, you know, tell us a little bit more about your background. As you said earlier, I was at SpaceX for five years. I was working on the Dragon capsule, which is a manned space capsule. Got to work on Starship a little bit as well. Cool. Yeah, so I was working on the... actuators for the flaps for Starship, which allow it to sort of, you know, act like a little bit of a lifting body as it comes through the atmosphere and then, you know, sort of navigate to the landing. Yeah. So that was really exciting, working with pretty high power systems. So on Starship now, that's an electric system. So there's high voltage batteries, there's big electric motors. That's really my background. Most of my roles have had something to do with motors or batteries or power systems. I've done that in automotive. I was at a couple of startups that were doing battery electric, road vehicles, motorbikes, fast cars. Working on that at SpaceX on space shows, which is kind of an odd one. And then after that, I founded Parallel with some other engineers from SpaceX. We were working on rail vehicles. So in some ways, what I'm doing here at Heart is a continuation of a theme. Yeah. You're collecting them all. I guess it's boats next, right? Yeah, boats next. But it's an exciting space to be in. It's moving super fast. Obviously, we're seeing success in electric vehicles on the road, huge advances in battery technology, improvements on the propulsion side as well, electric motors. And so aviation is really the hardest of all of them because you have really high power demands and you also have really high energy demands and you're incredibly mass constrained. So what we're doing at Haar is really the first baby step towards... decarbonization in in the aviation sector and this is a this is a huge incredibly difficult problem the technology doesn't exist today to build long -haul aircraft that are electric right but it does exist to build you know small regional aircraft that are battery electric right so that's really what we're trying to do yep cool cool so how did you find out about heart like how did you end up there and you're and you may as well talk about your role too yeah Yeah, yeah. Well, so I'm the CTO at Heart. So Heart was started in California as part of Y Combinator in the Bay Area. And then the founder, Anders, moved the company to Sweden back in 2019. And the goal there was to, you know. you know, service a market that is, you know, much more common in Northern Scandinavia than it is in the US. These sort of short regional flights, you see a lot more of those. And then also, you know, leverage the aviation talent that exists in Sweden. So Sweden, you know, relatively small country, but has exactly, yeah, Saab and SKF and, you know, various other, you know, like core industrial. you know engineering companies long long lasted yeah long lived yep um so um so move the company to sweden and grew the company and obviously heart found uh you know market fit in a way that many of the other sort of regional uh electrified uh aviation startups um you know struggled to um so really compelling product and story, but as the company grew and got deeper into development of the product, realized just how challenging this engineering product is. It's not something where you can integrate batteries and electric motors that exist in the market today because they just don't exist. All the technology has to be built from scratch. And really when you're thinking about building the aircraft, integrating the aircraft, You know, the battery weighs, you know, 30 plus percent of the mass of the dry aircraft. You have to really design that in from day one. So you have to design the aircraft from scratch. If you don't do that, you're never going to get the efficiencies that you want in the structural design of the aircraft and get the performance that you want. So the focus of the company over time kind of shifted from, you know, what we originally saw ourselves as more of an integrator. you know, shifted towards a company that needed to be more vertically integrated. And so that's, you know, when Anders, you know, looked at, you know, where the company was and, you know, where in the world, you know, you can find that sort of experience designing, you know, clean sheet vehicles, electric vehicles. And, you know, he really... found himself pulled to LA, to the California ecosystem, particularly the LA ecosystem. And so I got involved with the company around that time and now we've actually shifted all of our engineering operations and our headquarters. here to LA. Right. Which was big news. And it's interesting. You talk about it. We started out as an integrator and now we think ourselves as more vertically integrated. Like, I mean, to me, yeah, I totally get that. You know, I mean, most of the aviation community today is built around, you know, I make this and you make that and somebody else integrates, you know, there's air firm, there's some propulsion companies. And, but yeah, I think I agree with your premise that that's not going to work. Right. And so at some point you. Yeah. Okay. Interesting. And I can also see why California, you spelled it out, but that was my guess, right? You've got Tesla, you've got SpaceX. If there's two companies doing clean sheet, throwing everything away and starting from scratch, it's those. So how might you absorb some of that talent? By the way, when you look at the industry, today there is a lot of disaggregation. The big players outsource a lot of the design of the avionics and propulsion and even structural manufacturing in some cases. That's not how they started out. And when the big names today were sort of developing their aircraft. you know the first time around they were much more vertically integrated right so you know what we're doing is is not really you know uh you you sort of mentioned you know throwing it out and starting from scratch and it's not really the intent of what we're doing it's you know we're kind of responding to this um you know technology paradigm shift um and you know you have to have that level of design ownership that level of vertical integration yep to really uh you know get the design right when you have this big you know, sort of like foundational technology shift. Yep. And, you know, that's what we're doing. Yep. Awesome. So I kind of want to talk about the ES30 powertrain next. Yeah. And I think you guys stand out. Right. Like if you think about the EVTOLs, it's all sort of battery electric and which kind of in the vein of the ES -19 in a way. Right. The previous aircraft. And then you've got other players like your Volteros and not so much Viridian, but definitely Ampere, you know, parallel hybrids. You know, I think, well, technically, Voltero often flies independent hybrids now. but they're talking about going towards a parallel hybrid for where they're going with the Casio. So a lot of folks are sort of moving in that direction. But, you know, you guys, I really, I like the movement between the ES -19 and the ES -30, but I have to imagine that there was conversations about that, right? Like, and how we got there and everything. So do you want to start by, I'm kind of hinting at all this stuff. Like, how would you tell the story of the ES -30 powertrain and how you got to where you are? Yeah, well. we see the ES -30 as an aircraft that can drop in you know pretty directly to existing airline operations for these you know shorter regional flights and be a workhorse of these kind of you know short regional routes and so um you know to achieve that um you need to have you know first of all really good economics so that's that's really our focus pretty much everything we do is it's focused on how do you get really good economics um and so um you know passenger count is an important factor there um you know even with the es -19 you know our goal was to basically push the passenger count as high as we could push the range as high as we could um within the part 23 um sort of limitations and What we found as we did that is that we were left with an aircraft that was somewhat compromised, really mass constrained with battery technology that exists today, if you try and stay within the Part 23 mass budget. And your economics in a 19 -seater are also pretty challenged. And so that pushed us into Part 25. And so within the Part 25 framework, The ES -30 really represents what we think is the largest aircraft that you can build with battery technology that exists today that makes sense. Your range for your electric vehicle is somewhat independent of the size of the aircraft. If you have a 6 -seater or a 19 -seater or a 30 -seater, your achievable range is... is about the same. It's sort of in the range of 125, 200 miles, which is where we're sitting right now. And that's because the mass of the battery is so dominant. If you want to double the range, put twice as big a battery in, the entire aircraft needs to grow, maybe not twice as much, but almost twice as much. And then your passenger sort of paleo mass fraction really shrinks down. So that's what's driving us. If you build a bigger aircraft, if you try to build a 70 -seater or 100 -seater that's battery electric that has a range of, you know, 120 to 200 miles, that doesn't make any sense, right? You know, aircraft that are 100 seats, they need to be going, you know, 400 miles, 500 miles, 600 miles to make sense of the airline. Sort of economically. Yeah. Yeah. So that's where we sit. And obviously, as battery technology improves, you know, so that's the… the basis for the ES30 sizing. The ES30 is a hybrid, and it's a hybrid so that you can meet the P25 and IFR requirements using conventional fuel, which is obviously much more energy dense than the battery. If you try to meet those requirements with purely battery, powered aircraft like the s19 was you end up carrying a huge mass of battery that you know gets used maybe 100 flights um so it's really inefficient to do that you're carrying that mass around for every single flight and you're using it one percent of the time um so what about when you say ifr i i think we're getting into like oh how much reserve do i need and when you say the different like part 23 and 25 like i think i vaguely know that part 25 is like transport category but can you can you break it down a little bit like what is it about the jump to 25 or or ifr that means you need a bigger battery is it just that reserve or is it something else yeah so the the part um sorry that the ifr reserves um are 45 minutes of flight time plus the distance to your alternate airport okay so you know we typically use something like 100 miles as a sort of a nominal distance to your alternate airport obviously depends on the route that you're flying so your energy reserves even depend on a specific route but but even even if you just look at the 45 minutes that's similar to the average flight time for you know one of our flights or even in some cases longer so it's a huge amount of energy that you end up carrying if you try to carry that in the battery yep um and you're right so part 25 is a transport category airplane so that's you know your 737s your um a320s of the world um part 23 is um normal category so if you um like a cessna or okay you know it's a small aircraft so the 19th seater ES -19 was designed to be, like, basically on the upper end of the... Fits into, okay, fits into the bottom, okay, into the top of 23. So 25 would include, like, a Q -400 or an ES -19. Sorry, you guys are the ES -19. I guess I mean E -195 or something like that. Okay, gone. Yeah, exactly, yeah. They're all in there. And the safety requirements for Part 25 aircraft are higher, so it's a more challenging category to certify an aircraft in because, obviously, the expectation is that you're... typically carrying, paying members of the public in regular scheduled airline operations. Okay. So we've touched on a number of things. I think of you guys as an independent hybrid as opposed to, say, a parallel hybrid, right? Or a series hybrid, right? And if series is, you know, sure, there's a combustion engine somewhere, but all it's doing is charging a battery. In my mind, I think that's serial. Parallel is like, you know, they're both spinning the shaft, the drive shaft at the same time, whether that's, or the propeller in this case, whether it's the battery and the electric motor or the internal combustion engine, you know, they can both do it. But I think of you guys as another thing. You have both at the same time, which is cool, right? And like I said, I like it. Like I could immediately see it and like kind of understand it, which I liked. But what trade -offs does that bring? Like what don't we know about what... independent hybrid does to the decisions you're making as an engineering team? Yeah, so there's a couple different things that we're looking for. So one of them is how do we build a really reliable aircraft? So safety obviously is of extreme import. So the nice thing about having the independent hybrid is that you have a turbine you have an electric motor you can run either of those systems you can run both of those systems and they're largely um you know as as the name says independent um you know if you have a fault of some kind in your um electric power chain obviously there's levels of redundancy there to sort of reduce the probability of that but if you if you were to have a fault um you know your turbine you know it doesn't really need to know about that it can operate independently um so that's that's really exciting um to us Should help with certification too, right? I mean, you just choose a certified powertrain and hopefully that helps, I imagine. Yeah, yeah, exactly. So that's the second part here. So the turbine on the wing in our independent hybrid configuration is very similar to how the turbine is installed in other aircraft. So it's an existing turbine that we're using and it's mounted in a fairly conventional way. From the perspective of the turbine, there's really not that much new about our aircraft compared to any other aircraft that you might be flying today. Which makes regulators happy. Yeah, so there's a lot of really good things about it. Now, obviously, the efficiency of the aircraft is also really important. We want to get the most range that we can out of the batteries. And whether we're running on battery or on fuel, we want to use the least amount of energy because that's obviously a driver for the cost of operating the aircraft. So with this configuration with the independent powertrains, there is a trade -off there, right? Because you've got additional drag from having additional nacelles and additional propellers on the aircraft. So we're really working pretty hard here on continuing to improve the propulsion configuration for the aircraft. And we're pretty early into this. There are no aircraft out there right now which are... which is a hybrid you can buy today. Correct. So we're like really on the cutting edge here and, you know, continuing to explore, you know, like how do we continue to improve the efficiency, improve the reliability of this propulsion configuration, just build a better aircraft. So, right. So drag, obviously. I mean, yeah, that seems to me like it would be the obvious one. Maybe a weight penalty you're carrying around some, not dead mass, but. I guess it depends on how often you see it operating and which use case. Like if it's going to be operating on battery sort of, I don't know, 60 % of the time, then that turbine is maybe dead weight. But is it the other way around though? Like if you're operating with the turbine most of the time, is the battery system dead weight? Or I don't know. How do you think about it in that way? Yeah. Well, we think that our customers will typically be operating in the electric mode and try to operate in the electric mode because the economics is going to be the best there. So that's what we think our customers will try to do. So you need to carry reserve energy for this IFR minimum, right? So the 45 minutes plus your distance, your alternate. So you can do that by carrying additional battery or you can do it by carrying, in our case, we have the additional turbines and the fuel. And, you know, because the fuel is so much more energy dense than the battery, even with the weight of the turbines, we're still, you know, very much. the advantage is very strong to carry the turbines and the fuel rather than the battery. So that's how we're making that trade -off. Yep, got it. But you mentioned the drag first, so I imagine it's drag over mass in terms of the hit that they're bringing to the performance penalty. Yeah, yeah. So the drag is obviously significant. That's part of the equation for sort of optimizing the aircraft configuration. You mentioned earlier there's a number of different ways that you can do a hybrid configuration. You can do a series hybrid, for example, in a series hybrid, which we've had various configurations in the past which have looked at the series hybrid. And in that case, you have the turbine with a generator, and then that communicates electric power to the... So the nacelles where you have thrust produced by another electric motor. So in that case, you only have two propellers rather than four propellers, right? So there's a drag advantage there. And obviously, there's other trade -offs associated with that configuration. So yeah, so obviously, the goal is to generate the best economics for the aircraft. You want to minimize the total operating cost, which is the function of drag. And it's a function of the size of the battery that you have and the mass of the aircraft. And so that's what we're focused on is how do we achieve that. Cool. So one of the questions I sometimes think to myself about is, and apologies if this is a rabbit hole, but how independent is independent? Like when some of the hybrid systems that we see... I think like Electra, you know, definitely in that series configuration, ES2, ES9, very much the generator has to be running pretty well all of the time. But that's more of a function of battery size. I assume ES19 did not have to have a combustion engine to fly. And I assume that that means you guys had already solved significant engineering challenges around pneumatics, hydraulic systems, you know. de -icing, you know, HVAC, all of the things. But yeah, I guess answer my question instead of me daydreaming like I normally do. How independent is independent? You've hit on a really good point, which is that it's not as easy as just taking out the turbines and replacing them with electric motors. And this is true of anyone who's working on electric aircraft. There's so many systems in aircraft. today which are powered by the turbines right so the pressurization of the cabin is powered by you know most aircraft the bleed air from the turbine and the flight controls in most aircraft is most turbine aircraft is hydraulic and the hydraulics are pressurized by the turbine and so if you if you remove the turbine or in our case you still have the turbine but you're not using it all the time you don't have those systems available so you need to you need to produce those things in some other way. So our flight controls are going to be electric. We're going to have a distributed electric flight control system. Our cabin pressurization is going to be electric as well. We have a really big battery, which is helpful. And by the way, you're seeing this trend in... conventional aircraft as well. So the 787 adopts several of these systems for sort of secondary flight controls and systems related to cabin environment control as well. And the reason that you switch from sort of your engine power supply to your electric power supply is a mass savings, right? If you don't have to run hydraulic lines through the aircraft, then that's a mass savings. It's also a reliability savings. various incidents in the past where hydraulic lines have been ruptured, and if you rupture a hydraulic line, you can lose several systems at once. Electric systems are generally more robust to that. It can also be an efficiency improvement. So there is a general trend in the industry to try to get towards more distributed. Electrification, yeah. Exactly, yeah. We had Ed Lovelace from Ampere on, and I asked him, what's your favorite aircraft? And he said the 787. Did he say it's like 1 .4 megawatts worth of electrified? I mean, I'm not sure if I've got the number right, but it's a lot, and it's impressive. Yeah, yeah. Yeah, yeah. The scale of aircraft is always, you know, you go from, you know, our RAS -30 is a relatively big plane when you stand next to it, but then you compare it to a 787 or an A350 or something like that, and it's tiny. We'll get there. We'll get there. Yeah. But, yeah, always incredible to, like, see the scale between small and big aircraft. um so yeah so you know obviously the technology that we're looking at really forces us into some of those decisions um but you know we see it as a favorable decision overall but it you know obviously it does um just reflect you know the challenge of of going to a new power source going to an electric aircraft there's so many things that need to be rethought re -optimized uh because uh you're changing your propulsion system yeah i think of like the way you guys started with the you know battery -only es -19 sort of approach kind of giving you a leg up in some of the ancillary systems. I think everybody else kind of gets to kick that can down the road, which is a benefit to them, I guess. They don't have to deal with it, but you guys already have, or you're at least in progress on it already. So I don't know. I think it gives you kind of an interesting leg up. It's interesting. Yeah, we had to buy that bill early. Obviously, a lot of the EV toll and advanced air mobility companies are tackling similar problems. Our aircraft is pressurized. Whereas some of those aircrafts are not. So there's different but similar challenges there. One of them, which I love and won't name, but doesn't even have air conditioning. When you watch them on YouTube, the dude is wearing gloves when he's up there flying it. They don't even have HVAC yet, much less they have pressurized cabins. And I don't know how de -icing is going to work. But to your point, carrier class, there's a lot more systems that you're going to have to think about, right? I should ask if you're doing, I forget, do you have landing gear? Well, I mean, obviously. But does it extend and retract? So the prototype that we're flying next year, the X -1, has fixed landing gear. So when we release videos of that, you'll see the landing gear do not retract. But in the production aircraft, they will be retractable. Yeah, okay. So right, even more systems, right? And you guys will be forced to pioneer. Yeah, on some level. Okay, cool. Right. OK, so this means you definitely also have to get good at charging. Right. And a lot of the parallel folks and even some of the series folks aren't bothering. I'll ask them, do you intend to use CCS or GBT? And they're like, yeah, we're not doing it at all. You have to put gas in it in order to make it go. But you guys, if I remember right, in Hangar Day 2024, talked a fair amount about Charin, right? And the megawatt charging system. If I remember right, there was even like the triangular face of it, you know, being plugged into an aircraft. So, yeah, I mean, I don't know. Tell me about charging and how it's different on aviation to other things. And what's it like working with MCS so far? Yeah, yeah. So we've done some demonstration projects. We've shown publicly some work on charging. So we're looking at MCS megawatt charging standards. Our battery. in the production aircraft is going to be i'm not going to give that specific capacity but it's going to be a little bit north of a megawatt hour okay um so a megawatt is uh you know you have to charge faster than obviously than a than an electric car you know electric car charges are typically around the sort of 150 to 350 kilowatt range um we're going to want to charge you know around a megawatt for our So this is 3x to 333 or something, like roughly 3x automobile? Yeah. It's not 30 or 300x, it's 3x, yeah? Right, exactly. Yeah, roughly 3x. And it's similar to the power level that you would charge a semi -truck with, an electric semi -truck on the road. And actually our battery size is also very similar to a semi -truck. Yeah, okay. Which is quite interesting. So that will allow us to... recharge after a typical mission so we use for typical mission we use something on the order of 125 miles you know from you know origin to destination um so sort of like ground distance and then obviously the aircraft you know it's climbing it's consuming a lot of power it's flying the cruise mission then descending and then there's some taxi time on either side but our typical mission is 125 miles and we'll be able to recharge after that mission in roughly 30 minutes okay um so that's that's uh obviously allows us to fit into conventional uh airport operations a conventional turnaround is on the order of you know 30 to 45 minutes so within that time period you'll be able to you know recharge the battery the energy that you depleted over that flight um and um you know obviously standardizing on uh MCS gives us access to that ecosystem. There's a huge amount of work that's going into that for particularly trucks on the highway. So that technology, we can basically directly reuse that and some tweaks for the aviation use case. But generally speaking, it's the same technology. If I remember right, MCS is essentially CCS, but, you know, sort of scaled up. But, you know, similar. Obviously, the electrical specifications are much higher. But otherwise, very similar to Charon CCS in the end. So to your point, half an hour turnaround. Yeah. So you're going to have to taxi. And, well, obviously, everybody has to taxi. So I guess just like with the gas engine. aircraft you know you're going to be pulling the the fuel hose to it right away same thing with this you're going to be getting the the electrical and we sort of saw that in action in the hangar day videos on in 2020. um okay cool so we tried to minimize the impact on you know airlines and airport operations you know obviously it's not exactly the same as a conventional fuel aircraft today there is you know you do need to get it hooked up Relatively soon when you get to the gate, if you want to have that full charge window, it's a hybrid aircraft, so there's also fuel ports. So depending on the mission that you're flying, if you're flying a hybrid mission where you're consuming both electricity and jet fuel, then you would need to fuel the aircraft as well. And then there's often aircraft, particularly at regional airports, are fueled by fuel trucks. Whereas the electric infrastructure, you can't put that on a truck because it needs to be plugged into the grid or a large battery. So that's going to be located probably close to the terminal so that you can plug it in when the aircraft arrives at the gate. So there's a few differences here operationally, but really we're designing it to be as easy to integrate as we can for a typical airline. Got it. I guess you could do a charging truck, but you don't want a battery to throw at it. More batteries. Yeah. Batteries for your batteries at that point. Yeah. Right. That makes sense of what you're thinking about it. So one question I've got, I don't know if you've taken a look at Joby's geeks or G -E -A -C -S system that they've been. Did you guys review other standards? I totally get it. I mean, to your point, Tesla Semi, MCS, I think Volvo, MCS, like so many of the trucking companies, I want to say Peterbilt. I'm not sure. I'm not super expert there. But from what I understand, a lot of the trucking industry has sort of said MCS all the way. I can see the intelligence and like, this is a thing. It is obtainable. This is going to be commoditized. It's also going to be tested like crazy by others, right? Yay. But did you look at, I don't know, did you think about any other standards or what was the selling factor? Was there a decision around that or was it a pretty quick call? Yeah, so JB is working on... uh charging standards and um from what i understand that the emphasis there is on kind of the front end you know so maybe on the back the charging equipment is similar to what you would use in an mcs system but on the front end they have um redundancies that you can charge multiple independent battery packs with less hardware on the vehicle, which is exciting, particularly if you have a smaller, lighter aircraft. And so the mass penalty of having the switch gear on the aircraft to sort of isolate the different packs is more expensive. And then the other thing that they have, which is really interesting, is the fluid port so that you can... use ground -side cooling equipment to take heat out of the battery in the aircraft. And take some mass out of your aircraft instead of having to have liquid cooling on board. And then there's other, I think Gamma did a white paper that you can read about where they sort of proposed a common charging standard. And I think Joby was not involved with that, but many of the other... um ev12 companies were and it was you know kind of similar to the the jb center that you mentioned and then i think that's turning into some kind of an industry standard or proposal right now i think there's some drafts flying around uh in in the industry on that so yeah it's quite an interesting challenge i think i think many of the ev12 companies um have been doing a lot of work on that for us um our optimization um is a little bit different because obviously our our peak power demand is lower than it would be for an ev tall and we're a fixed winged aircraft so our sort of peak power load is as high as it's lower than if you need to sort of vertically take off yep um so that means that the batteries that we're looking at and the cooling system that we're looking at is a little bit different than a typical um ev tall and the other thing is that you know our Aircraft is just physically larger, so some of these systems that we're talking about, the penalty is lower to include them in our aircraft. Fair. Right, right, right. We're exploring these options. I think that this technology is advancing quickly, and obviously airports are involved and thinking about how it affects their operations. So we're certainly paying attention to it. considering it in in the trades that we're looking at but um Yeah, right now we're looking at the MCS system. Cool. There's a little bit of podcast time travel to do here because I'll be releasing the Joby episode soon, so you could not have watched it. But they're going to be talking about how they intend to be. They really need to focus on getting certified, obviously, is my take from what I can tell. But I think they're interested in getting the standard out there more than they have in the past. I think they've sort of always kind of wanted it. with that one PDF that they put on X and that's really it. And a single email address. I think they intend to do more. So watch this space, I guess. Yeah. But of course, you can't watch it yet because we're still finishing touches on the editing. So yeah, I'll just put that bird in your ear and we can move on from it from there. And I think it's really exciting how collaborative this industry is. There's different players working on electrified aviation. There is a lot of... cross -pollination, there is a lot of sort of collaboration on standards. I think, you know, J .B., some of the others, certainly thought leaders and, you know, very proactive at, you know, getting these ideas out there and trying to work with others to advance the industry as a whole. It's fun watching it for me right now, that's for sure. And I think part of what you're saying is part of why. Yep, no doubt. If you could get one free breakthrough, what challenge would you solve with it? well i think you'll probably get the same answer from most people working on electric aviation i mean my my thing would be you know if we get 600 to a thousand watt hours per kilogram at the cell level or at the pack level that would be amazing yeah would really enable a lot a lot more in electrified aviation um so yeah i think most people would say that battery is the uh No doubt. I think they would want to push the wood. There was a light on moment for me when I realized cars are sitting on the ground, Kyle. They don't have to use their energy storage to keep themselves in the air, right? And doing so via fixed wing, you get lift, which is nice, as opposed to having to do it all with a rotor, which is great. But it still costs energy to keep it in the air. So, yeah, every ounce counts, and it's just different. We had this tipping point moment, I think, with automotive where it was – I was talking about this with Ed. BMW put out the i3, which was their series. hybrid uh automobile um right around the same time well in order to solve a problem that was common of evs back in that era which is like they've got like 100 miles range maybe um i've got an older kia soul ev at home and it's got 111 miles range you know and it's still going we love it but that's just not a lot and bmw was like we can solve this with a range extender and they put a little you know three -cylinder engine in the trunk And this is right around the time that the Model S comes out. And they're like, oh, you could have just put a thousand laptop batteries in it instead. Right. And so I think, you know, uninformed me just sort of assuming like, yeah, of course, we're going to see the same thing in aviation. But yeah, we will eventually. OK, the batteries will get better. And then at some point you'll be able to build an ES30 equivalent that will be. You know, all electric, won't have the turbines on. And at the same time, we'll be sort of pushing up to the higher range. And, you know, the IFR reserves, you know, being able to carry enough energy so that if you miss your approach and you need to fly to an alternate and you're in inclement weather. And you don't have the ability to put the aircraft on the ground. You know, this is a real challenge that automotive just doesn't have. Right. Yep. Like a typical driver might take their car down to, you know, 5%, 4%, 3 % of the energy in the car. And that's totally fine. You can do that very safely. That's right. Worst case, you pull over and you call an Uber, right? Yeah. Exactly. Yep. And you just can't do that with the aircraft. So you're always carrying this huge battery reserve or energy reserve in some form in order to protect against that fairly unusual case where you just can't land the aircraft because of weather and you have to go fly to another destination. So that's a huge difference. And it's a real mass driver if you try to do that with just the battery. So there's always going to be... a category of aircraft where the economics are really driven by that nominal flight right 99 out of 100 flights right i'm flying within the capacity of the electric system the battery i can get the economics of the electric aircraft and then 100 flights or even even more infrequently i need to turn on that turbine and say my economics are going to suffer on that one percent of my flights Um, but at least I don't have to carry that mass every single time. So that's, that's why hybrid aviation, um, it's a more direct solution to the problem than, than it is in, in automotive. Um, you know, my belief is that if it's possible to electrify the flight, so for example, these, these short distance, a hundred mile flights that we're looking at with the ES30, if it's possible to electrify it, that's going to be your cheapest overall system, right? Because Relative to any other energy source, electricity is going to be the cheapest. And then you have the batteries, you have the electric motors. The electric motors, relatively inexpensive as well, last for a long time. The batteries are a little bit more expensive, a little bit more life -limited. But overall, you're still going to be in a better place than if you... use another energy source, whether it's conventional fuel or it's hydrogen or some other energy source where you have round -trip inefficiencies that sort of drive the cost up. So I think that electric aircraft, when they're on the market, like the S -30, they're going to win for the routes that they're capable of flying. And then as the technology improves, eventually you'll get to the place where you can... You can say, okay, like for these short flights, we can be all electric. We can remove the turbine system. We can make the aircraft a little bit cheaper by doing that. But you're also going to be pushing into those longer flights at the same time and saying, okay, like now we can do 300 -mile flights with a hybrid aircraft. Now we can do 400 -mile flights with a hybrid aircraft. Right. So let hybrids be the pioneer and battery only can sort of come along behind it. Yeah. That's how I see it. I think that when the technology gets to that point, the short flights, electric only, that's going to be the way that we really lower the cost of flying as much as we possibly can. And then the hybrids, you will realize cost savings with the hybrid system as well relative to a fully conventional aircraft. And we'll just keep pushing that up to get the most range that we can. Cool. So 600 to 1 ,000. Press release universe, you know, MagnaX or MagnaX, I guess, is talking about 400 watt hours per kilogram. I think CATL is talking about 500 watt hours per kilogram. But, you know, that's press release land. I mean, I don't know anyone who's actually getting to procure that anytime soon. What are you seeing? I mean, you're in there dealing, talking to manufacturers, talking to OEMs. Is there something on the horizon coming? Sometimes I worry that as an industry, Aviations like demand won't be big enough to force the weight curve down as fast as the price curve has come down. Lithium batteries famously just get better and better every year on a price perspective, but the mass side is harder, right? What are you seeing when you're talking to OEMs and providers there? Well, automotive is driving both the cost and the mass of cells down. The energy density in cells is improving as a function of automotive demand. That's really exciting. And I think that you're right. The reality is that the aviation demand for sales today is not large enough to really drive the innovation that we need. So that innovation is being driven by the automotive demand. And that's really exciting because, as you say, the press releases that we see, there are huge improvements happening all the time. When we look at cells, there's silicon -rich cells that are starting to hit the market now that are going into some automotive applications. Price point's a little high, so they're available for aviation applications as well. There's some semi -solid -state cells which are starting to get into pre -production. There's some solid -state on the horizon, which is, I don't have anyone that's using... solid -state cells in aviation applications yet, but that's coming soon. Batteries, it typically takes quite a long time to go from your prototype to something that's, you know, manufacturable in volumes that you can actually ship to customers. With good yields and everything else, yep. We had a previous guest on that was talking about how the way he sees it, that energy battery density is sort of somewhat like a trade -off with safety, right? It kind of makes sense. I mean, just on the face of it, the more energy in the battery, the more there might be a possibility of thermal runaway. But I don't know enough to be able to validate that. What do you think? It's a complicated topic. There's some chemistries that were looking at the silicon -rich lithium ion designs. Some of those cells you're packing in. um more energy but you are there is a safety compromise there um you you know like the the the uh not necessarily the energy emitted from the cell during a run of event but but also the sort of like the the rate um so the aggressiveness of the of the thermal event okay it's higher so you know for some technologies there's a trade -off for some technologies you know there's really promising results from some of the solid state concepts where you really don't see those highly aggressive thermal events it's it's a really complex um engineering challenge and you mentioned solid state too right like solid state also has a has a function here i i take it those are safer i guess there's less flammability because the the electrolyte something but this isn't my area yep yeah i mean you know those cells are generally not in production they're a little bit further out on the horizon or the ones that are in production um are not necessarily getting the cycle life or the discharge rates that are that are necessary um so there's um i would say that we you know we're going to learn more about solid state cells over the next few years yeah um but you know there's there's a lot of different um advances happening in different directions and different technologies, different areas. And so, you know, it's quite a rich landscape. Do you see any other, you know, future possibilities for emissions reduction? I mean, we've talked a fair amount about like, you know, 600 to 1 ,000 watt -hour kilogram batteries and how that's not, you know, immediate horizon, but we're seeing some improvements to your point. And I like how you talked about having hybrids sort of push the envelope and then battery electrics coming behind. Well, that's the way I phrase it anyway. But do you see other trends or other technologies that could be involved in reducing emissions in aviation? These technologies that we're talking about really apply to the shorter distance flights, say regional and then short haul, at least for the next. you know a few decades like that's the kind of area that we're playing in for longer distance flights there is you know some opportunity to employ hybrid systems um to improve the efficiency of you know the engine particularly you know around takeoff and so there's some opportunity for hybrid to to have an impact there but you know as you get to longer and longer distance flights uh you know the sort of marginal improvement you get from the hybrid system It becomes less, and you spend more of your time in crews. From an emissions perspective, long haul is a real challenge. So there's various technologies in research and in various stages of development for that. There's obviously synthetic fuels, which if we can get to a good cost structure there, that could be really exciting. There's hydrogen. blended wing design. So, you know, for example, is working on, you know, just, you know, significant aerodynamic improvements to the aircraft to really reduce your emissions that way. So it's a really hard problem to solve. And, you know, I think that, I think there's a lot of interesting ideas and innovations going into it, but I think probably too early to tell, you know, what the outcome will be. A couple of miracles needed for some of the SAF stuff, but maybe fewer. Hydrogen, it seems like a good number of miracles, but gosh, is it compelling given how much energy you can pack into a hydrogen atom. Yeah. Okay. Cool. Yeah. Hydrogen is certainly interesting. This definitely challenges the volumetric density and also the handling of the fuel. It's an easier shift to add some electric charging stations at an airport than it is to support less conventional fuel. Automotive has really struggled, right? I guess there's fewer airports than we would need gas stations, so fine. It's probably worth the research. But yeah, there's a couple of miracles in there for sure. What about lessons you've learned? Anything that you, you know, used to think was true and throughout this journey or through your journey in your career, things that you, you know, used to think that were true and now you don't see it that way anymore. Well, I think that we talked about this a little bit earlier, but I think that vertical integration in the development process, and we're not talking about designing every single bolt, owning every single bolt that's on the aircraft. uh you know a broad supply chain that we're leveraging um all levels of complexity just the way you said that it makes me imagine that you have designed a bolt though at least at least one maybe but but i follow your point though yeah sorry keep going um yeah i personally have not designed a bolt yep got it got it um but yeah so you know what i really mean is owning The design and you know, it's the design that matter and you know, this is such a complicated aircraft we're introducing new propulsion systems the batteries the electric motors were Addressing the complexities that arise because of that so we talked about the flight controls Earlier and the environmental control system pressurization of the aircraft There's structural challenges you know how do you you know where do you put the battery how do you fit it in a way that's structurally efficient um that allows you to have the lightest you know wing and aircraft structure as well um so so there's a huge number of um nuances and complexities yeah in the development and so like really having ownership as an organization of that full stack and being able to respond to discoveries um as you prototype as you fly aircraft as you as you understand um you know better the technology that you're building and then be able to respond to that quickly you know get back out on the test stand you know within a week or within a few days right right with a new design and try something new reducing your cycles there yeah being able to learn faster yep yep so and i and i you know i think that this is true about any radically new aircraft technology that you're introducing and i think that um There's a strong and growing community of startups out there that are sort of tackling these challenges and building the skill set and building the organization to handle this. And I think that's really exciting for the industry as a whole. I think it's going to inject a lot of energy into the industry. Cool. Awesome. What are you most proud of? Well, I'm really excited about the X1, which is our prototype aircraft that's in Plattsburgh right now. I think the team has done... Really phenomenal work on that. When it flies, and we're hoping to fly in Q2 of next year, we're in integration and testing of the aircraft right now. When it flies, it will be the largest aircraft by mass, all electric aircraft. Wow. So that's really exciting. It won't be the largest wingspan. I think Solar Impulse has us on that. Sure, yeah. But it is a big plane. So that's really exciting. So we're pushing hard to make that happen. And then obviously we're continuing to work on our future prototypes as well. So you're testing X2 as battery only? I assumed it was going to be full independent hybrid, you know, with the turbo prompts and everything. X1 will be battery only. It's an all -electric aircraft. It doesn't have the turbines. And then X2, which is our next prototype, will have the turbines as well and be fully hybrid. Got it. Okay, that's cool. I live too close to Plattsburgh, New York to not want to ask for – but I can only imagine that you would keep your fresh flights under wraps. So never mind. I'll reach out for LinkedIn later or something. You might see it, but you probably won't hear it. Oh, that's a fair point. That's a really fair point. Okay, so we'll head into the lightning round now. So what is your favorite airplane? Oh, well, there's a lot of airplanes I love. You probably get this answer a lot, but the SS -71 I think is a fantastic airplane. That's now the second time we've gotten that one. Yep, yep. I love that plane. I'm a big fan of Kelly Johnson. I've read most of the books about him. I'm a huge fan of his approach to... you know engineering in general you know just getting teams really close together yeah um putting them right next to the wind tunnel um just really like trying to like accelerate those those feedback loops and and the results you know obviously were incredible as well you know he's he was building planes yeah there's one aircraft that he built in um i think under 100 days um from sort of like kickoff of the project to first flight wow incredible stories oh my god and he did all of this obviously without um you know simulation tools that we have right right computational dynamics and like no none of that yeah yeah yeah not even 3d design tools yeah exactly and the s71 obviously is an example of an aircraft that um incredibly challenging if you were to approach that today you know yeah yeah there's a few engineering teams in the world that i think could recreate his results on that yep cool what's your favorite airport my favorite airport i have a private pilot so um not a not a serious pilot but you know casual pilot but i fly from la into catalina and i think that's very cool that's a that's a pretty cool airport for people who aren't familiar it's uh i think it's about 2500 feet up in the air on a mesa um so when you fly into it you're sort of flying over the cliffs of catalina and then they have a a great little restaurant um up at the top there so you can sit there and eat a burger and you know occasionally military planes will come and buzz it for fun so that's awesome out of santa monica or lax or there's lots of choices yeah cool cool there is a uh a vellus electro that that often shows up out of santa monica yeah yeah electric planes out there in the real world that was not yours no no okay yeah you got it okay cool yeah so my next question do you have any shout outs anything that's giving you joy right now that you want to talk about Anything that's giving me joy. I'm not sure. I didn't prepare for this one. I imagine you're working a lot. I'm busy. We just moved into a new office here in Torrance in California, so I'm excited to be in the new space. A lot more room for hardware, so we're going to be building parts, building systems. I guess that's what I'm excited about today. Okay, that's cool. That's cool. That's worth it. And then, yeah, I guess just a final question. Where should we follow you? Should we check you out on LinkedIn or Twitter? Like, yeah, where should we follow you? Yeah, so we've got a, obviously our website, our aerospace .com. We do post on LinkedIn. We have a YouTube channel, I believe. So we're trying to get some more material out there. We're going to have some. videos of, um, revulsion testing going up in the next few months. Um, obviously we've got the flight of the X one coming up. So, um, you know, hoping to fly that in Q2 of next year. And then obviously we'll, we'll have some, uh, media, um, around that. So yeah, hoping to have a lot more to share in, in the next few months. And, um, and then, you know, obviously continuing to, to, you know, prototype and push forward. Awesome. Awesome. Ben, thank you so much for spending some time with us today. We really appreciate it. Great conversation. Thank you. It's been a pleasure.

We are laser focused right now on getting through the certification process, getting the production ramped up. As soon as that's done, which is coming very soon, we are going to publish the specification and begin very detailed talks with the other industry stakeholders to potentially publish this as a standard. we will be in parallel to that supporting the commercial rollout of our systems. So there's some first vertiports that are already in the works that are already being constructed today, and we need to supply chargers to them. Formerly the captain for an electric car racing team for the University of Waterloo, where he studied, who later co -founded a robotics company that made pitching robots for the Chicago Cubs, Robert Rowland is an engineer on the ground support equipment team at Joby Aviation. where they are developing an all -new charging system to address the unique challenges of high -tempo electric aircraft operations, creating the critical infrastructure needed to make widespread zero -emission air taxis a reality. Robert is also our guest today, and this is the Sky Zero Podcast. with Joby talking to us about the GEACS charging system. So Robert, thank you so much for taking the time out. I really appreciate you taking the time to come speak to us today. Yeah, of course. I'm excited to share more of what we've been working on. Very cool. It's been pretty secret up to now. Right. You know, it's weirdly hard to get information about GEACS sometimes. Should I call it GX or GEA? I keep spelling it out. It sounds silly. What do you call it? Most people internally seem to call it geeks for now. No way. But I think it's still up for debate. We don't have a hard idea on how that's to be said. Okay, that's awesome. I'm calling it geeks now. That's just too cool. So yeah, let's start with you. I mean, talk about who you are and a little bit about your background. Sure, yeah. So I'm a mechanical engineer. I went to the University of Waterloo in Canada, which is a co -op program. Got to work for a bunch of cool companies as the... over the course of that co -op program including like toyota babcox and wilcox tesla apple and then a ev research lab where i got to see some like very early days uh r d efforts that general motors was uh was doing uh in the electric vehicle space And then I was also, during my schooling, part of the University of Waterloo Formula SAE team for the electric side. So we were designing and building an electric race car as students to compete in a student competition. And that's where I initially made a lot of connections in the EV world and really got my feet wet working on all aspects of designing and building electric vehicle systems and kind of fell in love with that. When I graduated, I went and did some other things for a while. I designed pitching machines for Major League Baseball. And I went to work for Apple eventually, but then felt the pull back to the EV engineering world. And one of my close friends from the Waterloo Formula SAE team, Alex Bondarenko, heard me grumbling about being bored with other work. asked me to come back to jovi to work on uh charging very cool i came back in 2021 cool cool so so uh personally i'm in toronto so i mean waterloo means a lot to me that's really neat uh i i i'm aware that i had an sae team that's really cool did you guys win that year is this the big australian race or am i getting that wrong uh we have performed well recently but not not one Great. Thank you. That's really cool. So to your point about getting connected, it was a fellow Waterloo alum that pulled you in. Okay, cool. What's it been like so far? How have you found it working there? It's like a super exciting company. When I joined in 2021, it was only two people working officially on the charging team at that time. There had been some different efforts across the company to build charging solutions for Joby's early aircraft. They had always been more from the perspective of just like get it done and explore different ways to charge the aircraft. And then starting in 2021, there was a concerted effort to actually make, okay, like what are we going to do long -term? And that was the beginning of what became GEACS. Kind of before I joined, there'd been a lot of research on different aircraft architectures. how eVTOLs might need to be designed to perform well in an air taxi environment. And they came to some of the conclusions that drove the decision to build GACS. Yeah, tell me about that. I was going to get to it, but I imagine they looked at... CCS and GBT and sort of all the others, or did they just, or maybe, I've known, definitely have known teams that were pre -inclined to build versus bring in. But how, did they sort of look at those and say, oh, it doesn't meet the spec, or to your point, they were really looking at, like, what would an air taxi need, right? So what about that led them to build and, yeah, like, just start talking about GCS, basically. Yeah. Sure. Yeah. So, I mean, that's like something we definitely want to do always. If there's an off -the -shelf solution that meets our needs, of course, we want to buy that. It's always cheaper usually to buy something than to make something. But when Joby's thinking about operating air taxis, we need to not think about like the cheapest solution just for charging or the best solution just for charging. We need to think about the whole picture. How are we going to operate? air taxis in a way that is efficient for the whole system and safe for the whole system and it turns out that when looking at the global optimization problem it's worth it to trade some more complexity onto the charging system and in some cases move some of the cost of the overall system onto the charging system in order to yield some overall benefits so by Moving to a system like GACS versus CCS, we can charge faster, we can have a safer aircraft, and we can get that aircraft to have some additional capabilities that wouldn't otherwise be possible. Yeah. So I'm sitting here biting my tongue because I've been looking at like there's this one PDF you can get on Twitter. If you search for like... you know, GX geeks. Um, this, it's this one thing that comes up and it shows you like what, what it looks like. Um, you know, and then at the Oshkosh air show recently, I actually got to hold the handle for the first time. I'm like, okay, wow, this is great. You know, like the, the engineering on it. Oh, you've got one right there. Yeah, of course you do. Yeah. But for folks who are just tuning in and they have not spent as much time obsessed over this as I have, or not nearly as much as you have, right? So walk us through, because it is pretty different, right? If you think about CCS versus GDEMO versus GBT, they're pretty similar. There's some communication pins, and there's DC and there's AC, and that's kind of it. But with geeks, it's pretty different. So walk us through what those differences are. Yeah, so GEEX, I should say for a second, is really just a definition of the interface. It is defining the boundary between the vehicle and the charging system. And right now, there's only one implementation, Joby's implementation of GEACS. But in the future, once we publish this as an open specification, hopefully being adopted into a standard, we think that... There will be many other implementations of GACS with different ground systems and different ways of aircraft connecting and using the charging system. That standard consists of, or that interface definition, consists of fluid ports, so we can pump fluid on and off the aircraft. In our case, it's 40 % ethylene glycol with some corrosion inhibitors. And then we have two independent DC charging channels, so we can independently send plus and minus. two separate independent channels to charge in our case two separate battery packs and then we also have a data connection so in the middle it's kind of hard to see with the lighting but we have a set of pogo pins that allow us to communicate between the aircraft and the charging system one way and also have some interlock functionality between the aircraft and the charger so they can both agree that they're in a safe state and then The remaining pins are to provide auxiliary 48 -volt power from the charging system to the air. Oh, okay. And you are 48 -volt auxiliary. Right. I want to deep dive in all of the places at once. And that's difficult to do in a conversation. So let's start with the liquid part. Because to me, that's the part that usually blows people away. It's like, they're doing what? I remember when I first got an EV, my neighbors were like, can you wash it? I'm like, well, yes, of course. Can you charge it in the rain? And of course, right? And when I explain, that's the thing about geeks that makes it so different is, or to your point, that's just the interface. But that's what makes the Joby charging. systems are different, is that you are running coolant through it and not just electricity. So let's start there. Walk our listeners through why. Would you do it that way? I've got my guesses, but I want you to tell the story. Sure. So specifically on the... fluid side if we take a step back for a second and think about like how do we charge faster uh what is the limiting factor at a physics level to charge a battery very very fast and usually at the end of the day it's actually a thermal problem um batteries battery cells have this like complex matrix of variables or factors that affect the ability to charge and discharge the battery cell and the most important one of those is temperature If the cell gets too hot then you risk going into thermal runaway so you need to slow down the rate you are charging or discharging the cell to ensure you don't exceed that temperature limit. If the cell is too cold then if you charge too fast you risk lithium plating or other negative effects. on the cell's electrodes that could limit the life of the battery pack. So when we are designing a charging curve, so the relationship between state of charge and the current we're going to push into the battery pack, we're constantly looking at for that specific state of charge, what temperature ranges do we need to stay inside? When you're dealing with large battery packs that are charged fast, you're almost always going to have some form of active thermal management system. In your automotive electric vehicle, pretty much all EVs on the road that are built recently have some sort of liquid cooling system where they're pumping liquid through the battery pack to some form of heat exchanger, like think of a radiator in the front of the car, which air passes over it and cools that coolant down, and then it goes back to the battery pack. And it's not just about keeping the battery pack cold, but you also have to bring the battery up to temperature. So they'll also have a heating system in that loop. Those systems, you have to strike a balance between the amount of mass and the amount of volume you're going to take up in the car versus the amount of cooling capacity you have available. So in your average EV, oftentimes when you hook it up to a very high power DC fast charging system, they're going to charge at a high rate for... few minutes in some cases, and then they're going to slowly start tapering off the power, not because the charging system you're connecting it to doesn't have the power available, it's because you're starting to over -temp the battery. The thermal exchange system on the vehicle wasn't designed to continuously reject the amount of heat that's being generated by the battery pack during charging. So when we sit down to design an aircraft, we have to think, okay, do we want to put a active thermal management system onboard the aircraft and how much continuous heat rejection capacity did we want to design into that thermal management system governing how quickly we can charge. And in an aircraft, the... Mass is very, very important, like far more so than an automotive application. We want to shave out every possible gram that we can out of the system, especially for dead weight. So a cooling system is considered dead weight to us because it's not energy to extend the flight, and it's not generating power, and it's not structural necessarily. It's not like supporting the airframe. So that mass, every additional... unit of mass that we add in dead mass means that we have to add mass elsewhere in the aircraft to support it. Right. So if that liquid cooling loop took up, I don't know, 100 pounds, probably not that much, but let's say, and you could take it out, then that's 100 pounds more people. you can carry uh and and and of course there's these famous equations around weight and aviation where it can actually be even better than that sometimes i'm probably getting it wrong but basically you can size everything else smaller uh the smaller you get so yeah That's what I wondered, right, that we're able to take it out. And to your point, like if I charge my EV on a hot summer day and then I'm driving down the highway after and I still have the AC on afterward, like the heat pump is running like mad. And I think it's because like I just like supercharged, you know, the Ioniq 5 charges at like 230 kilowatt or something. And so it's using the same cooling system to cool down the battery and us. And I've never heard the heat pump go so loud as when I've just been charging. Does this mean you get to take all active cooling off board? I mean, I guess if you're operating at like 4 ,000 feet, it's cooler than when you're sitting on the asphalt in Phoenix in the summertime. But how much cooling are you able to take off board? Do you still have some on board or not? So in the Joby aircraft, we actually have no active thermal management systems on board the aircraft for the battery packs in flight. thermal management systems that are rejecting heat to the outside environment. We do leave coolant on board, but that's not for the purpose of rejecting heat. We do have a thermal management system on board the aircraft, but it's for the cabin. Just an air conditioning system to cool the cabin. And that is also something that is enabled by GEACS. So batteries are very dependent on being within an optimal temperature range for their state of charge not only for the charging process but for the discharging process so with GACS if we keep it connected right before the aircraft takes off we can bring the battery packs to an optimal temperature for takeoff and then in an air taxi environment you're usually doing short flights we can identify what the next flight is going to be and bring the battery packs to a temperature before that next flight that is going to be able to see them through to the landing. Right, right. You've got a decent thermal mass. It's going to take time for its temperature to have changed too much. And right, in short times, we're not talking about eight hours across the Atlantic here. Okay, neat. So that's considerable weight savings, and you're able to find a lot of dead weight there. That's neat. Massive weight savings, and we're also able to have a much bigger, more powerful cooling and heating system. in an off -board system where we don't care about mass, we don't care about gallium, we can go buy a chiller off the shelf pretty much and stick it 100 feet away from the vertiport with a set of lines going to our dispenser and we can have far more cooling capacity on the ground to be able to exert a high degree of control over the temperatures of the battery pack throughout the charging process. So we can keep the battery packs in that optimal temperature range throughout pretty much the entire charging sequence. Amazing, amazing. What can you say about what this does for your charging curve? I can't share any specific numbers for the currents and voltages that we're running with, but I can say that GACS can support up to 1 ,000 volts and 300 amps continuous. Wow, wow, wow, wow, okay. Okay, but also I'm thinking about sort of shape. And to your point, can't talk speeds and feeds, and I get that. But if I think about, like, I mentioned my Ioniq 5. I'll be an automotive nerd for a minute. It sort of goes, like, high, and then it stays high for a little bit, and then it doesn't come down that much, but then it sort of flattens out. And then sort of around 60, 70, it starts to really kind of slow down, right? And other cars will sort of like – like the Tesla famously is like – goes really high and then sort of comes down really fast. And they're almost like encouraging you to like gas and go quick and don't sit there forever. But then other cars, they sort of get to like – I don't know. 70 and just sit there the whole time you know and that's in part because of limitations they've got when i think about your charging curve should i am i going to imagine like one of these mountains that goes high and stays like a table or is this more like a high curve that's got then flushes down or can you talk about the shape of the curve yeah so due to our ability to control the temperatures of the battery packs we can stay at high currents for longer right which is the big part of why GACS enables faster charging. It's not because we're going to higher absolute powers. It's because we're able to stay at high powers for longer. Right. Right, right, right, right. Got it. Which usually ends up winning in the end instead of a super big number at the beginning and then slowing it down. Okay. Awesome. Awesome. Cool. Thank you. To your point, two DC channels. If I remember right, on the S -4, the charging port is under the wing. So I think I just assumed that there would be one on each wing. But if there's two DC channels in the one port, is that right? Is there sort of just one for the entire aircraft? Or how does that work? There's two charge ports per aircraft. Got it. Okay. So each Joby aircraft, which is the first one that we're launching, has one charge port on the left and one charge port on the right. And when that aircraft comes into land, we plug two identical GACS charge handles in. So each wing has two batteries. So you're talking a total of four. Correct. Got it. Okay, cool. Cool. Which, again, is better for redundancy and everything else. And if I remember right, charging speed, too, I guess. Although, if you're putting all of that into one big cable, But it still seems like it would help with charging speed. Is that right? Yeah. If you were to combine it into one handle, you could do that. If we were to have four of the same size channels as we're putting in our two -channel system in one cable, you could do it. The limitation might just be the mass of the cable. These cables are already getting quite heavy. But that's not the reason why we did what we did. There's other reasons to click the... keep the charge ports separated on the aircraft, both for keeping the systems isolated and not having mass passing over the center of the wing. Yeah. Hopefully one day someone from the charging team can come on and tell that story. Got it. Sorry, from the aircraft team. So we covered the liquid cooling system. We covered DC inputs. Were there other types of things about CCS that you wanted to improve on? Yes. So when we began developing Geeks, We were initially focused primarily on safety. We still are. Safety is our number one priority. And then we also wanted to get to faster charging. And in looking through what was required to enable our standards for safety and charging speed, we started to see some desires in... cybersecurity, our ability to pull data off the aircraft, and where we were doing the computation for optimal charging that necessitated a better data and communication pipeline than existing charging standards such as CCS could enable. CCS has the option to use power line communication to transfer data from the vehicle to the charging station, but it's limited to about one megabit per second. And our math indicated that we wanted to go far beyond that, multiple orders of magnitude, more data bandwidth. So what developing an all -new standard unlocks with GACS is that we could add a new means of transferring data between the vehicle and the charging station. We added a 2 .5 gigabit per second T1 Ethernet connection. uh in the charge handle connection in the charge interface that allows the aircraft to stream data down to the charging station in a secure fashion the data stream is limited in hardware to be one way so there's no cyber security risk in that interface okay but the aircraft can stream vast quantities of data about its current state through the charging process as well as just general purpose data let's say if we want to transfer data from the previous flights records of the previous flights down to the charging equipment we can do that and that enables us to one have a faster charging season i'll talk about in a second but we can have data available on the ground support equipment that's been securely pulled off the aircraft that can be used to analyze the current state of the aircraft for predictive maintenance, for example. So we can see, is some component onboard the aircraft trending in a bad direction? We can then preemptively or proactively schedule maintenance work that we otherwise wouldn't have been able to know that we needed to do. Got it. On the charging side, With existing charging standards, the decisions around the charging process are primarily made on the vehicle side. So the vehicle looks at all of the sensor data that's coming in from its batteries, its records of what the batteries have been up to over the period previous to the charge, and it decides, this is the voltage and current that I want to be charged at, and it sends a current limit to the charging station. And then the charging station basically just tries to do its best to get up to that current request. We wanted to go beyond that. When you're running an air taxi operation, you have the opportunity to forecast what is the next mission this aircraft is going to be doing. What is the current state of the power infrastructure at the building where the vertiport is situated? What is the current state in our case of the cooling system? And knowing all that information allows you to maybe make a different decision than you would if you only had the information that the vehicle has on hand. So by streaming a large amount of data from the aircraft, in this case like raw battery temperature data, individual cell voltages, pressures of various points in the fluid system, we're able to have a higher... more complex level of charging optimization by transferring all that to the aircraft, running computations on board the ground support equipment with more computational power to make a decision for the optimal charging profile. So there's another weight savings there. We can now have more computation because it's part of the charging system, or is there more to it? Yeah, so it could potentially be a weight savings. You could have... more complex computing hardware on the ground it's also a benefit from a continuous development perspective so anything on board the aircraft in the sake of safety we want to have anything that goes on board the aircraft any change to the software or hardware on board the aircraft has to go through a very very rigorous review and testing process but for charging we might want to continuously update uh the optimal charging sequence for a given aircraft maybe every week we want to be continuously pushing small little tweaks and updates to optimize that process which if we were to put those algorithm optimizations onto the aircraft side, we would be very delayed in our development process. But by having it on the ground support equipment, we are freed to be continuously updating in a much faster way. We still go through a rigorous review process, but it's not quite to the same levels as is necessary. for an aircraft that you're trusting with your life. So I think about Tesla doing over -the -air updates. Maybe you can do that with the S4, but to your point, it would still have to go through like a full certification round. And so now, by being able to make this software changes to the ground support equipment instead, yeah, it allows a faster... Wow, so you're really speaking my language on the continuous delivery side. That's a very software thing to do and thinking about how can we continuously... get the software updated. Okay, cool, cool, okay. So I guess the one megabit per second that CCS did have, I can see that being as maybe enough if all you're doing is saying, this is how many amps I want right now, this is how many amps I want right now, over and over and over again. But to your point, you're doing a lot more with it. Okay, neat. For us, it's very, very critical that the ground support equipment is not able to modify the aircraft in any way that is not immediately and reliably detectable by the aircraft. Right. That's what drives this. Got it. Cool. So famously, you guys have flown in Dubai now. With some digging, I found that you guys did some serious flying in Korea, right? And almost like a championship kind of competition kind of situation. And of course, there in Marina, K -O -A -R, I think, is where you normally do your flying. So at least those three locations, right? And there's a fair amount of difference between those three. When you think about what it takes to charge and how the situation changes it, like, yeah, what can you say there? I mean, have you learned anything taking it to different situations, for instance? Yeah, absolutely. And we're also currently flying in Osaka, Japan, every day. That's right. And we flew at the Salinas Air Show. How did I forget Osaka? That's the one that's happening now. Yeah, and there's a host of others. When we developed our actual charging system to support aircraft flight testing and continue supporting the aircraft, we took kind of a phased approach where we started off by building a very agile, lightweight charging system out of a series of power supplies connected directly up to mock -up charge cables. And then after that, we took that solution, we learned from it, then we built a next -generation charging system that... allowed us to pack all of the functional bits required to build a GEACS compliant charging system into a 20 -foot shaped container. We built a number of those systems and we've deployed them around the world. So every time you see the Joby aircraft fly in Osaka or in Dubai or for those Korea demo flights that you were discussing or at our flight test facility in Marina, that's all using that 20 -foot shipping containerized solution. And that's exactly the same functional system as we plan to launch commercially at our first VertiPorts. But now we are on the next phase where we're taking that system, we are miniaturizing it, we're packing it down into a system that can be integrated into real commercial sites, which have different kind of layout requirements and different spacing requirements. And we are currently now done the design phase for that program, and we are in the process of ramping up the manufacturing and going through the certification of it within NRTL. Oh, that's exciting. Okay, cool. So you should see some news about that system soon. When you say certification, my brain leaps in two directions at once. And one is sort of like, you know, UL or in Europe, there's a similar one, EC, I think. But you could mean FAA and EASA. What sort of certifications end up being required? So as this is a piece of ground equipment, we are able to certify it with a nationally recognized test lab in the American case. Those test labs usually offer... multi -market certification options where we can work with one recognized test lab. to certify the product in a variety of markets at once. So we're working with a test lab like that. This process is the same as the process we would use to certify any other automotive charger or even your washing machine or toaster in your house. UL is one example of a nationally recognized test lab, but there's others. Got it, got it, got it. Yeah, fair. So, okay, but we don't need to go the FAA route. They're not looking into this. No, we work hand -in -hand with the FAA. They are aware of what we're doing. But the aircraft is capable of ensuring its safety before the next flight. The aircraft is always monitoring the condition of the charging process and the condition of its batteries. And it's able to stop the situation at any time automatically if anything was to go wrong. And that's really what the FAA cares about is the safety of the aircraft. Right. It's more the aircraft itself and not the ground equipment is sort of what I was getting at. Okay, cool. So charging system architecture. avoided numbers, and I get that. In automotive, we think of it as, you know, there's sort of 400 volt and 800 volt. But also, it's not just the number, is it, right? It's sort of like the battery pack is maybe at one voltage, but then inverter systems might be at others, and motors might be at others. Like, how have you thought about the architecture? Like, what can you talk about in terms of, like, how are all the components matched up? Or I think it's the Hummer EV that I'm thinking of that's literally, like, it's too... 400 volt packs you know but so it's really a 400 volt system but it's kind of an 800 volt battery and so they could do the 800 volt charging or something i'm sure i'm getting all this wrong sure so the gacs standard uh is a thousand volt charging solution so and those uh the implementations of that system that we are building and installing uh can support the full range of the implementation so we can support up to a thousand volts independently across all four channels Joby's aircraft uses a range of that, a little bit below the 1 ,000 volts. And each battery pack that we're charging stays completely isolated and independent of the other battery packs. Right, right, right. So to your point, whatever that number is, it's not divided by four, it's times four. It's times four. So when I said we can do 300 amps, it's 300 amps times four. Wow. Times 1 ,000 volts to get your power. Right, right, right, right, right. Okay, holy cow. That's pretty insane. Yeah, that is definitely pretty insane. Gosh, is that megawatt level then? So it can theoretically support up to 1 .2 megawatts. Wow. For a single station install. Got it. So you're giving China one for its money in a way. Okay, that sort of gets into another direction that I want to go with this. You said earlier, you know, we want to... I don't know if open source is my words or yours, but release it, right, and make it a public standard, a public specification, if I understood you right. How would you see that working? Like would you, I mean, just to pick two other large North American OEMs out of a hat, like if Archer and Beta were suddenly, or if Ehang were going to suddenly start looking at this, or Heart Aerospace were going to suddenly start looking at this. Like how, what's the ambition inside of Joby for that? And yeah, it seems like it would be good in a general way if that standard were out there, I guess. But yeah, like how do you guys see it and what's the ambition for it? And yeah, talk about that part. So our ambition is to publish this GACS specification as a standard. eventually that can be adopted by anybody who wants to adopt it. That includes other charging equipment manufacturers and other aircraft OEMs such as the ones you mentioned. We haven't gotten there yet because we want to stay laser focused on focusing Joby's own needs. So being able to support Joby aircraft flying every day and also make sure that we retain the flexibility to modify our system as we're going through the certification process. There might be some last minute tweaks as we work with the test labs to get our system through to being a certified product that we can deploy. Once we get through that process, we fully intend to publish a full set of documents of the entire interface specification that can be used by other people looking to manufacture their own solutions. But in the meantime, our door is open today. And we have a email alias that anyone can contact. It's groundsupportequipment at jobeaviation .com. It was on the bottom of that PDF that you were referencing. there is an aircraft OEM or a charging equipment manufacturer that wants to reach out to us and start working with us today to adopt GACS or to suggest alternative design choices we are open to that and in fact we already have had a number of different aircraft OEMs and other people in the industry other stakeholders reach out to us express interest and provide alternative suggestions some of which we have implemented yep I don't know if you got a chance to read it, but I had published – actually, I think you might have – an article about charging, right, and aviation versus automotive. And I sort of wrestled with it. It's like – so I can totally see the allure of something like CCS. You could charge the F -150 Lightning that's airside that's getting crew around at the airport on an apron or anything else that you've got, which is a ground vehicle. I mean, that's a benefit. to something like CCS. But at the same time, like the combined in CCS means combined AC and DC, and nobody's doing AC charging in aviation right now. They're all doing DC charging. I assume that's for the same reason as what you talked about earlier, which is that that AC equipment on board is extra weight that you don't need to have. So like CCS is one party trick in a way is that it does both and you don't need that. In fact, it seems like it could be extra. If not weight, at least volume. I mean, these are not small plugs. Like the one that you were showing is also not small, but you're getting a lot more out of the footprint. You're getting cooling, data, and two separate DC loops. Whereas with CCS, you're getting one DC loop, and you're not getting any of those other things. So I can totally see what would have pushed you guys that way. I think also, I think it was Josh. port lock at um out of australia for electro electro electro the one that doesn't make an airplane the one that makes chargers um was talking about how the thing about ccs that's kind of not great um when you're plugging it in horizontally it works pretty well like that's how cars go but when you want to plug it into a wing it doesn't and it's not that it doesn't have locks it does but that those locks generally weren't implemented with this orientation in mind. And so they're more likely to fall out and be dangerous and cause shorts and things like that. So yeah, all of this to say, like, I can see why you guys went the way you did. But have you ever had a heartache about that? Like thinking like, does it make sense for ground vehicles to also use geeks as a potential down the road in order to get some of that value that CCS brings? I mean, I couldn't have been an easy... conversation i guess is where i'm going um yeah i mean if you want to talk about that at all yeah certainly so we don't take the decision to develop a new solution lightly um like the the proliferation of new standards is is not something anybody wants like we would like to consolidate to one solution yeah um I think that there are other industries that would probably benefit from adopting GACS eventually, especially once we've done all the work to develop it and it's out there and available. It might make sense to adopt it. But what really drives it and the main use case to make a new solution is just air taxis. The mission is just so demanding and unique that... If you want to operate eVTOLs in an air taxi environment efficiently, we see something like GACS as really the only solution. You can't have just a CCS connector and efficiently operate air taxis because you're just going to be spending too much time on the ground or you're going to have too heavy of an aircraft. Yeah. I mean, the cooling, being able to operate your cooling, certainly to me, that's like, okay. I get it. You know, it's worth it at that point. And being able to combine two and one isn't bad either. So, yeah. So could we imagine an airside – maybe I should stop trying to make it so that airside ground vehicles can use it too. I don't know. I mean, is that crazy to think that airside ground vehicles maybe – they don't have the same challenges, but – I guess I'm trying to save a buck for small airports that don't want to have multiple charging systems out there, I guess. So they could adopt it, yeah. And GACS is quite flexible because of the way the communication protocol works to do a range of different things using the same interface. So you can plug in a vehicle that, let's say, only has one battery pack, and you can just tell the charger that, hey, your two charging channels are now paralleled. We've connected them to a single bus bar on board the vehicle, and we want you to charge in unison, and the dispenser will happily do that. Same deal if you were dealing with a vehicle that doesn't have cooling, let's say, or has a different cooling temperature range. You can command the ground charger to not use the cooling or to follow a particular temperature profile that's needed by that vehicle. I haven't seen any driving forces for that yet, but it's not to say that it's not possible. Yeah. I mean, it seems a little bit silly. I mean, could I actually imagine like an S4 taking off and then somebody pulling up an F -150 Lightning? I mean, it seems like probably no, like you may be having another one land shortly after, but I don't know. Just, but I'm, yeah. So thank you. Thank you for humoring me on that one. I appreciate it. The other consideration is that, These chargers are installed airside. And at FOBs, there's a high degree of control between airside and general public. So it's not like the general public would ever be able to pull up to these. And most of the vertiport sites that we're going to be operating at are also separate, elevated structures in urban environments or in other areas where you don't necessarily need to have ground equipment around. Right, right, right, right, right. Yeah, I've got to start thinking vertiport and not airport. You know, I mean, airports have baggage handling trucks and all sorts of stuff running around, but a vertiport may or may not yet. Yeah, they may be smaller and choosing sites that are tight might be something you want to do. Okay, fine. I get it. I get it. So you definitely need that mini system to your point. Yeah. What can you say about the miniaturized version? When I say miniaturized, we're miniaturizing the dispenser. So that's the piece of equipment that gate keeps the flow of liquids, coolants, and the data and the electricity on and off the aircraft. We're taking that piece of equipment and making it as small as possible such that we can fit it into creative locations on these very constrained vertiports. So vertiports have some restrictions on clearance zones you need to have a big circle around the landing pad that needs to be kept completely clear on the surface of the landing pad and then also there's restrictions about where you can place things even outside that zone with like a cone that expands out from the landing pad so we want to be able to either put them low to the ground to the side of that landing pad, or in some cases, even under the landing pad and pop up through the surface of the landing deck. Got it. Okay. Got it. So instead of like a 20 foot, you know, TEU container, you know, where we're talking about something that it's almost sounds like it might be distributed to into sort of multiple modular components, like part of it's under the pad or? Yep. So we're taking a modular approach where there is a dispenser. which the actual charge cable pops up out of that has to be at the landing site or wherever the aircraft taxis into for charging. And in that... dispenser there's a core module which houses all of the functional bits to do with the charging process and then we package that core module into different configurations uh to be reused at many different sites so we're going to have a mobile solution that's on wheels and you can drag it around and we've also got a solution that goes under the ground such that you can have a completely flat landing deck and then when you need the chargers it pops up out of the ground and you can connect it to the aircraft very quickly and efficiently And then the dispenser, I think I said it's just the gatekeeper. It's connected to AC to DC power conversion equipment, which thanks to the automotive market is largely commoditized. We can buy AC to DC power conversion modules from various markets around the world for very, very competitive prices. And then... On the fluid side, we're connected to a large coolant reservoir, so an insulated tank of coolant, which is then connected to a chiller. The tank serves as like a capacitor for the coolant, so when we first connect to the aircraft, we have this big reserve of very cold coolant to pump into the aircraft. without having to size the chiller necessarily for the peak thermal exchange rates. Okay, cool, cool. So componentized, modularized, and also sort of, yeah. Okay. So it sounds like certain things like that coolant tank could almost be sized up or down based on use case, need, available space. But to your point, this does also allow you to sort of go with sort of commodity equipment, like you're saying, the ACDC equipment from the charging side. Okay, cool. Cool. That definitely makes more sense. I mean, for now, having it in a shippable container makes a lot of sense. And I think in certain circumstances, disaster relief in terms of, like, were there a natural disaster? Yeah. I mean, a shipping container is, again, exactly what you would want. Of course, that's a disaster that's going to have to have a very large electrical connection still. But still, I could imagine it being dropped into place in a lot of different places and used. But, yeah, in a vertiport, that's a big, chunky. cubular thing which is kind of in the way so yeah all right cool thank you can you talk about partnerships at all like when you think about um current collaborations strategic relationships in the charging ecosystem anything you can speak to there unfortunately no i can't share specific details beyond what's been already publicly announced uh but you can see from our other public announcements we've got pretty strong relationships with toyota delta uber ana and a bunch of others yeah toyota especially They've been very, very supportive of us. I run into members of the Toyota team every day at our San Carlos site. Nice. Okay. Yeah. And there's also multiple ways to book a Joby flight through those partners. So you've probably seen our relationship with Uber that may enable us to book a Joby flight through an Uber and do multimodal transit. Let's say with a car share on the start of the ride. that is synchronized with your ability to take a Joby flight and then have a car waiting for you on the other side. Yep. The story where you guys sort of started out of Uber Elevate is such a neat tie -in, right? I mean, you can totally imagine you guys having Uber at launch and just having it work, where you can't necessarily imagine that with anybody else. But I think that's a part of my question for you guys around charging, too. We don't know how this is going to go in aviation. There's not a lot of aviation charging networks yet. It kind of is. Aerovolta in the U .K., which is very, like, general aviation, trainer -oriented, the little GBT, Pipistrel's. E -Grid in Switzerland, very similar. There's a new one, Energy to Fly, out of the Netherlands that I'm talking to right now, and they're doing exciting things too, GBT and CCS2, if I understand it. Beta, of course, right, with the 40, 50 stations across the northeastern U .S. and even the southern U .S. and one in California, if I remember right. But, you know, so I can imagine all sorts of companies buying a beta aircraft and needing a place to stop and charge it. And I can imagine them either throwing a mini cube in the back and using the GPU, ground power unit, or, you know, plugging into a beta charger. With you guys, it's a little bit different. Like, I don't really want to get too much into, like, business model, but it probably impacts some of your decision making. Like, could I ever, what would the need be for a Joby? geeks charging network would you imagine that or i almost imagine you guys doing it a little bit more like an apple style like no no no we take care of it all for you like you don't have to think about where it charges um but maybe i'm wrong like i don't know how i got to that assumption right what what can you say about like how you envision the charging that you're working on getting out there in the world yeah so it it depends on the path to commercialization for the market that you're talking about. This is not my area of expertise. Right. We've laid out three paths for commercialization in the quarterly earnings calls. So one of them is a Joby owned and operated air taxi service that you alluded to in which we would control the full stack. We may also do direct sales of our aircraft. And then there's partner operations, like what we're working on with ANA. Right, right, right. Or Delta, maybe. Okay. So in each of those types of markets, there would be a different solution to deploy the chargers, which is my job. My job is to build GACS. certified GACS solutions and then we want to have that optimal charging system available to be deployed to those markets very quickly so we are like I said building it to be like super modular so we can deploy it really really fast and we've got all sorts of different options for how it can be put out so we have a solution for every type of vertiport or landing site And then we are also ramping up the production capacity to exceed the rate at which we're building aircraft. So you're never going to be bottlenecked by your ability to get a charger. Right. Right, right, right. It does seem like that needs to be kept up, right? I mean, if there's no way to energize these batteries, they're not going anywhere. Yeah. So like getting a proliferation of the equipment out there seems like it would be a big job. Okay. But to your point, like you and your, I wish I was the kind of person that read earnings calls. I should have done that as part of my strategy here. But to your point, it could be either like Adobe owned and operated, but there's also, we could sell the equipment and there's also operating with partners. Okay. So you could. imagine based on that like a geacs sort of charging network out there then whether it's like joe b brandon or not i mean there'd be all sorts of models for that okay but we might actually get hands -on with this as a as a aviation industry uh it won't all be behind under wraps okay cool yeah it won't be under wraps there's definitely going to be uh units that are able to be owned by other entities and if other entities want to start thinking about how to install a GACS solution, there's things they can start getting ready for today. So that's making sure you have a large grid feed available. You can start working on the space claim to install a system. And there's some other little details. We're probably going to start publishing some of those standards eventually soon or advisements. If anyone who's listening to this wants to reach out to us about how can I install a GACO solution, just send us an email. We're happy to send you over some documents. Okay. I imagine it wouldn't be too different than an automotive charging site. I mean, obviously, higher electrical supply and siting, obviously. Hopefully, it's sited near somewhere where these things can land. So, I mean, that's big picture. But otherwise, like... I don't know. Any other requirements that would be impactful? The only big difference from an automotive charger is just the layout of the dispensers on the landing pad. Got it. Got it. There's a range of options there. You can go and just place it at the edge at the disadvantage of having to land and taxi over. If you want to be more optimal, we have some other solutions that we can share to those that reach out to us. Hopefully we'll be able to be public about that soon. Okay. Cool. Cool. Thank you. Appreciate that. What can you, can you say anything about the future? Like what's, where's the standard going next? What's up next for you? So we are laser focused right now on getting through the certification process, getting the production ramped up. As soon as that's done, we're, which is coming very soon. We are going to publish the specification and begin. very detailed talks with the other industry stakeholders to potentially publish this as a standard. And we will be in parallel to that supporting the commercial rollout of our systems. So there's some first vertiports that are already in the works that are already being constructed today. And we need to supply chargers to them. Yeah, yeah, yeah, for sure. Yeah, big job. Kind of switching from design, build to manufacture, scale, you know, ship, deliver, implement, install. Yeah, biggest challenges so far in anything, you know, design, build, implementation, anywhere you want to go. I would say that the... We were able to get to the 90 % solution quite quickly. And then it's the next 90%, which really bogs you down. There's lots of little details involved in making a complex system like this. I can't say there's any one big, massive technical challenge that has blocked us. It's a collection of little things that you would not expect really being the bane of our existence as an engineering team. But there's no real big blockers. If I had to ask Santa for some solutions to some of our problems, it would basically be more thermally conductive, flexible materials. That would be a great one. A moment you're most proud of? I think once we completed the containerized system and really being able to stand back and look at it and say, this thing fully works and watching it charge the aircraft for the first time that's always a happy moment seeing your your baby actually do its job for the first time yeah yeah cool where can you talk about where that was uh marina california yeah okay cool i wondered if it was like oh we had to do this for the korea thing or or the or yeah okay okay makes sense you would do it at home first yep yep yep try to do everything at home first yep obviously What about, and maybe this is almost more career long and not necessarily just where you are now, but anything that you thought you were right about or anything where you've had to change your thinking, right, and learn something and realize, like, oh, no, that's actually not how this works. Anything like that come up for you? Sure, yeah, it happens all the time. I can't think of any, like... anything that would make a great story for a podcast but there's been lots of cases where we spent a lot of time designing one solution one set of geometry then like a year later we realized that it has a uh like a critical gap or we missed one measurement and have to go back and totally redesign it i can relate to that i mean in software engineering you're obviously it's it's it's a different story but you're you're often pursuing a design pursuing a design and like nope that didn't work i'm going in this direction now okay uh so what is your favorite aircraft sr71 yeah Because of the speed? Because of the engineering? Tell me the story. I just finished reading Ben Rich's book, Skunk Works. And I'm getting into Kelly Johnson's book, more than my share of it all. And I really admire how those teams operate. It's something that we as Joby look to. did the people before us develop these aircraft so fast with such a high rate of success? And we try to learn from that. And they were a very admirable team. Cool. I've heard a couple of stories out of that one, but I haven't actually read it yet, so I will go away and do it. So you recommend? I highly recommend you should read it. All right, cool. Favorite airport? SFO is pretty good. Yeah? How come? It's fast, efficient. They've got the new scanners. I like that it has a BART station. But I'm just being a public transit nerd, I suppose. Yeah, no, it's a pretty good airport. All right. Any shout -outs? Anything that you want to call out? Anything that's giving you joy right now or anything you want to shout out? I will say one thing for anybody listening to this that wants to get ready for Vertiports. We have people that own real estate, people that really want to get to their work faster. They want a shorter commute. How can they get ready for building a vertiport? And the number one thing is to start upgrading your grid connections now. If you are working on an airport renovation project and you are looking to upgrade your transformers for more air conditioning, take the time to put in the headroom for aircraft chargers. Ideally, we want up to 500 kVA per charging station. We can work with less, but... that much is ideal. Please, please, please start doing it now. Yep. Yep. These are not always fast permits to get nor, nor fast connections to bring in. Okay. No, good. That's a great call out. Cool. So Robert, thank you so much for being on the show today. We really appreciate you. This is a great conversation. Yeah. Thank you. Thanks for giving us the opportunity to tell our story.

Haroun Junaidi is the creator of one of my favorite YouTube channels, Electric Aviation. With a background in mechanical engineering and a PhD in renewable energy, he specializes in modeling and simulation, particularly in computational fluid dynamics. Currently working in the e -mobility sector, Haroun combines his professional expertise with his passion for aviation to advocate for sustainability and promote sustainable transport through his channel. And now, this is the second episode of Sky Zero Podcast. Haroun, I have to say how excited I am to have you today on the podcast. Thank you so much for making the time. Your channel, Electric Aviation, has been like a lifeline to me. When I first started hearing about the Papistrel, it was the Alpha back then, and I wanted to know more. Were there others and these kinds of things? Finding your channel on YouTube was just like a godsend, a rabbit hole that went really, really, really deep down. So I'm really excited to have you on the show today. Yeah. I mean, did I miss anything in your bio? Anything you want to correct or add? No, I think that's about it. Thank you for having me. And it's the very first time actually I'm revealing my face. I've never revealed it on my channel. So that's exclusive for you. Amazing. Maybe we'll have to do some sort of put the. episode on both channels or something like this that'll be up to you maybe maybe yeah we'll talk about it for sure so i was checking i've done about 112 videos by now and i've never revealed Wow. Yeah, that's right. I can, it's normally you with, I think one of the things that I love most about your channel is how you can cover a lot of information in a way that's very understandable and in a way that doesn't take very much time. You have a really concise ability to edit and to get it down to the essential facts and convey something that both like tickles my engineering like imagination, but at the same time is understandable. and sort of not too jargon heavy in a way that's difficult to understand. So I really, you can sense the experience you've built up. What made you start it? Like 112 episodes ago, how long ago was this? And what got you started? I started in October 2020. So we're just coming to five years now. But I really had to wait for, to start this channel because I wanted the stories to come in thick and fast because You might know that for YouTube, you need to deliver content consistently. You can't just have a story there and then come back after one month and upload something else. You have to have at least, you know, weekly content. So I waited till the time I got that because the electric aviation thing started in this sphere about, you can say, 2015. onwards but you know there would be one story here and then six months down the line there would be another story there it wasn't like you had a news that was consistent so i had to wait a bit and in 2020 i decided that yeah it's it's time that we have a channel i've got enough content um on my plate that you know i can deliver to the audience on a regular basis And around about the same time, there was a lot of excitement in the electric aviation world. There were eVTOLs was a fresh concept. Uber had released its urban air mobility white paper. And there were, you know, these new designs, which were really, you know, really inspiring people all around the world. It was in aviation, you notice that innovation is very little. And to see something new, innovative and fresh, people wanted to know more about that. So around about 2020, a lot was happening. And further on two years, there were even more stories. you know that at that time i thought right this is the time i got to do it right now so that's the background so show you forethought and planning in terms of thinking about like oh i'll have to have weekly content so you sort of had to have enough build up uh yeah okay cool yeah that's amazing so i think through the five years, you must have seen a lot of change, right? Like I haven't, I've been paying attention somewhat, but it's very recent where I've started to really pay attention. So you must have seen, you know, what, how have things shifted while you've been watching, you know, to sort of think about past, present, future arc, we'll get to, we'll get to future. But yeah, I mean, how have you seen it change so far? I think we are in a passage of lull right now, because initially there was very high expectations that oh everybody is going to have their personal flying machine but we are coming to the realization that the battery technology hasn't advanced as fast as we would have liked it to advance and in the last 10 years in particular you know we've moved to about a battery energy density of 250 to 300 watt hour per kilogram so not a lot of uh change and in fact we have now reverted to batteries that are much less energy dense but are safer um so we're still waiting for that um solid state battery breakthrough um so at the moment there's it's a period of lull but Three years back, you know, this sector was buzzing. But what I see in the future is it might climb back up again. With the advancement in the battery technology, there's some excitement there in lithium sulfur, the silicon anodes, and also the aluminum air battery. Honestly, the aluminum air battery is maybe one of my favorites on your channel. I went and found that there was actually a Canadian startup, but they specialize in aluminum air batteries. And I checked out their fuel cells almost, you tell me. But I remember checking out their website, and it was talking about it could be used in telcos. Yes, of course, but you could also use it maybe in airplanes. And I emailed the CEO and said, you should think about aviation. My friend Haroon says so. I didn't know who you were at that time, but I'd seen your one episode on it. That was one of my things I wanted to ping you about. Like, we've got to get into the aluminum air batteries. But I want to get back to the rest of your point. I do sense the lull, right? I mean, the way I experience that lull, and it'll be different because my own dynamic through the path has just been a little bit different. But for me, the lull is like... I remember thinking the Aviation Alice was going to be coming out soon. And I think you and I talked about how Wendover Productions did their – they did a really great video on the Aviation Alice and how – oh, gosh, I can't remember the name of the airline now, but there was this airline in the eastern U .S. that was going to buy a bunch of them. I remember actually putting a date on my calendar. They had said that they would be flying, you know, by a certain date in 2024, like a month. And so I put it in my calendar, like go to the East Coast and fly in one of these things. And of course, you know, that didn't happen. And then ES -19, the hard aerospace aircraft, which was originally going to be fully electric, right? And I'm thinking, wow, you know, we're going to have two of these things. Yeah, so the way I've experienced the lull is going from that to aviation is now pretty silent. And ES30 is now sort of an independent hybrid electric. I'm hoping to talk to them soon. So I see a lot more parallel hybrids these days, a few series hybrids, you know, the sort of EL9 and things like that. But yeah, I definitely see like a... A lack of ambition for battery only, I guess, is a good way to put it, except for maybe in trainers. Yeah. So that's how it occurs to me. Yeah. One thing that has happened in the last decade is that, you know, you take a battery, you push more and more energy into it. It's great for aviation, but also in a way it makes it unsafe. So you have to build more around it in terms of safety. contain that thermal propagation if there is one. So the benefit of having that extra energy density is kind of lost by having those extra components in there for fire suppression and stopping the heat propagation, et cetera, and having a very robust cooling system. So we've gone back to batteries that are more inherently safe. And that's what the EV world is using at the moment. So they've gone from lithium, from nickel NCM batteries, which is branch of lithium ion. Right. And from that, manganese cobalt, I think. Yes. Manganese cobalt and nickel. And from NCA or NCM batteries, they've moved on to lithium ion batteries. which are safer, but then, you know, the energy density is lower. So instead of 300 watt hour per kilograms, you are talking about 180 watt hour per kilogram. Yep. But at the same time, they're much safer. Yep. So people realized when, you know, initially when it came to EV, it was all about, we want the range, we want the range. But now people are realizing that They can do with less range, but they would appreciate the safety more. So the EV world has gone in that direction. Interesting. Whereas for electric aviation, we would require batteries that are much higher energy density. And the only place where I'm getting positive news of progress is from China. So CATL. has been developing a battery that they call the condensed battery. And if it comes to fusion, they've said that they have tested 210 jet on that, a 210 aircraft. Oh, I hadn't realized that. So if you've seen the likes of Cessna Citation, they've flown an aircraft of that size. Wow, okay. But they have kept the data. under wraps. So there's not a lot of information available regarding that. Citation is the business jet, if I remember right? It's a business jet. Yeah, it's a business jet. Got it. They have kept a lot of information under wraps, but I'm keeping a close eye on that space. And as soon as any information is available. I'll put it up on the channel. I think of them. They've talked about an aviation battery, and I assume that's the same one you're talking about. I hadn't heard it called condensed. But the two tons is coming to mind, something I'd seen in their press release. Yeah, I think of them. I also think of MagnaX. I think MagnaX has announced like a 500 watt hour per kilogram battery, something, maybe 400. It's doable if they're making a solid state battery. Right. A solid state battery with 500 watt per hour per kilogram is quite realistic. Right, right. I like how you're taking it to safety. I've definitely heard people in aviation talk about, you know, you can pull a car over. if you do have a thermal runaway event. And that's true. Not that I want my EV to have a thermal runaway event while I'm driving it, but I can pull over. And these things are somewhat slow. They're not explosive. I've heard it said that in aviation, we need to prioritize safety more. It can't be a managed thermal runaway. It has to be no possibility of a thermal runaway, or at least very small. And I don't think I'd put two and two together that that means energy density is the expense. I think of LFP and automotive as a solution to a price problem. But yeah, to your point, it's most likely also has a better safety track record as well. So I like how you're tying those two together. I hadn't seen that yet. Once I read an analogy, and that was quite nice. So I would like to share that. Think of the battery as an aircraft and the energy inside it as the number of passengers. You can either put more seats. and reduce the aisles so you will have more energy inside the battery but when it comes to getting that energy out it will be slower uh consequently if you have more aisles more gates and you will have less passengers but you can get that energy out quicker interesting so if you look at the lfp battery it is the battery which has more aisles to get the energy out quicker. So you can discharge it at higher C rates without any problem. And if you look at the other high energy density batteries, yes, they pack in more energy, but it's relatively difficult to get it out. Oh, interesting. So energy goes up, but power goes down in a way. Interesting. Oh, I hadn't thought of that. So there's another tradeoff to your point. It's not just safety. There's something I wanted to get into with you around, I still want to get to aluminum. We'll get to it. But another thing that's maybe equally science fiction or works in the lab. I don't mean science fiction. I mean it works in the lab, but we haven't seen it on the runway, would be structural batteries. And I think this probably covers a range of topics from using a rigid battery module as something structural in order to absorb crash dynamics and things like that. But I wonder, could you see something where... I don't know, a wing is made of batteries somehow, you know, or literally the skin of the aircraft were somehow a battery. Like, I don't like imagining things which are not feasible or just totally fanciful. But what do you know in this area? Have you followed much of the sort of structural battery area? What's promising? What seems far out but maybe possible? What do you think? If you look at the batteries that we had, the shape of them, So they were like cuboid. And how do you call it? They were basically like boxes, thin boxes. Pouch cells. Yes, a pouch cell or a prism cell. But now if you look at some of the new layouts that are coming out, they are called the blade batteries. And they are much longer. So they are extended. in their width, you can say. So the aspect ratio in one direction is very long. So it's almost like a wing shape. It has the same aspect ratio as a wing. So given that the new batteries are flatter and longer, you can adjust them easily inside the wings. So they can be a part the structural part they can provide the structural rigidity and we can pack more into the aircraft with a battery that has a form factor like that right right so so that's happening and it's called the blade battery they they designed it so you know in your traditional ev skateboard chassis you would have several of these batteries across the width of the car, but now you have just two of them. Oh, I see. That's, yeah. So they are that long. So with that form factor, you can also put them in an aircraft wing. I think that would be a good... Put in the wing, but that doesn't necessarily mean that they become structural to the wing. They're not... Yeah, I mean, you're certainly not, I don't know. I was almost imagining like a tubular containing cylinder cells or something like that, but the tube being something that was actually structural. But to your point, this blade battery, I'm thinking of it like a longer pouch, almost like a plank of wood. Is it to the point where you could use that as enough structural rigidity for the wing, or do you also have to have whatever components were there? Well, you probably need more to keep the extra weight up now. I guess. Yeah. I suppose you can place them in the wing closer to the fuse lodge, but if you put them further away, you would have to structurally stiffen the wing, which would defeat the purpose. Right. But with these new blade batteries, it's easier to package them into a battery pack compared to the old ones. You have lesser connections. It makes it more reliable. Right. Compared to, because, you know, each time, you have to weld the terminal on top of the battery, there's a point of failure. So with longer batteries, longer and fewer batteries, you have lesser points of failure. Cool. So another question I've got. is like what what's your favorite like i ask everybody what's their favorite aircraft and we'll get to that on the lightning round but um but for you specifically since you've covered so many different things i was just re -watching uh your synergy prime video uh the dbt uh yes and and that that thing is amazing i mean you you've covered so many really interesting concepts the solera 500 and so on like what's what stands out to you is like something that really captures your fascination yeah the synergy Prime is a good candidate for, you can say, a family -size aircraft. But if I were to look at a single -person aircraft, then I like the Pivotal Helix, formerly called Open Air Black 5. And it's the simplicity of that design. It's quite beautiful. All these new eVTOLs have either a tilting wing or a tilting rotor. But it doesn't have that. It just tilts the whole body up. So you've taken out that complexity just by clever design. And it's got eight motors. And the motors are basically the main recipe of their success. Because the motor weight is just two kilograms. And yet it delivers about... over 40 kilograms of trust. Wow. Wow. And they've got eight of them. You know, I sometimes am daydreaming about the scenario where There's a zombie apocalypse. And I got to have, I find myself little black flies hidden somewhere away. And, you know, it helps me to survive. I make these stories up in my mind. So, yeah, that is my one go -to aircraft. It's a shame that, you know, I can't afford it. We'll have to see if we can get them to sponsor your channel. Maybe. That could be fun. But yeah, another point, technical point that it kind of helps that aircraft is that every motor has a battery behind it, battery module right behind it. So they don't have like these bus, you know, these power cables running to every single motor. if you have your battery right behind your motor you essentially eliminate that weight so they've got like eight smaller packs and only the wires that kind of control those you know batteries regarding how much power that has to be delivered those thinner wires go all the way to the controller I didn't realize that. As far as main power wires are concerned, your bus bars are concerned, they sit right behind the motor. So it's a very short path between the battery and the motor. That's where they also save weight. I imagine the control cables would be lighter. Right. So the only cables that you do need are lighter now. Okay. So instead of sort of a single monolithic battery in the fuselage, it's instead distributed batteries. Oh, I didn't realize that. Cool. Yeah, so there are eight of them, so one for every motor. Very cool. Okay, cool. Good answer. Good answer. I like that. So we've kind of come to the present, and we've talked a little bit about my interesting future stuff. Now, I have to ask about aluminum air one more time, though. I'm so glad you mentioned it. I haven't seen you cover it since, so I wondered if maybe you weren't thinking about it again. But you mentioned it earlier, so you have to tell me. What do you think of these? Let me see if I remember how it goes. Something like an iron air battery, it's essentially the process of oxidation in reverse. It can store and generate electricity through the chemical process of air being exposed to the aluminum. What my fuzzy memory took from that that episode, and I wish I'd rewatched it now, is that, uh, essentially you have to completely recycle the materials upon every flight, like that there's no recharging. Yes. So which is why it's maybe, maybe more of why it's better to think of it as a fuel cell because there's no recharging. There's only recycling. But if I remember, there's these companies making these little sort of metal disks that you could sort of easily load into a cell and perhaps easily unload. So, okay, I've done my bad impression of this. Tell me how it really goes and then tell me what you're seeing. Well, basically, you have a bunch of aluminum plates dipped in an electrolyte. And what happens is as the... aluminum oxidizes. It produces electricity and forms aluminum oxide and that kind of breaks away from the plate that you have. It's like a rust that happens. It mixes with the electrolytes. So you have to also flush out, keep flushing out the aluminum oxide. So as more and more power is drawn, these place dissolve away so when you land or when you've done your mission all you have to do is replace them with fresh plates fresh aluminium plates and that's it you're good to go so recharging it is not a problem you have to have some place to kind of you know that recovered aluminum oxide solution that you have remaining. You have to keep that so that you can recycle it. Although that recycling process is energy intensive. But the benefit of that battery is you get four to five times more energy density compared to what you have right now. What about power density? Sorry? Do you still get the power density you need also? We do get the power density with it. So there has been an aircraft in the UK called Swift, and it has flown using that. Wow. So I was to go and see the demonstration for it, but unfortunately it didn't come to fruition. Oh, no. Yeah. But they did manage to fly it. The flight did happen, but I wasn't there to witness and record it. I'm kicking myself because downtown Toronto, over the last two days, Horizon, the company who's making the EVTOL where they close the veins. Is it Cabaret? Yeah. They had the Cabaret X7? mock -up just downtown, like on the street, as part of a celebration for mining and minerals or something. I don't know. A conference, I think. And I'm kicking myself. I wish I'd gone to see it. So I can relate to the feeling you're having about not having been there. But you're saying they did get to fly it, though. That's awesome. Yeah, they did. Okay. Just once? I can't remember the flight time, but it was more than an hour. They were airborne. Wow. That's pretty impressive. One thing you'll see a lot of development is in electric aviation is the two -seater trainer aircraft. So just like the Pipistrel Valis Electro, you'll see at least five or six other aircraft that will join the Pipistrel Valis in the near future. I know for sure there is buy aerospace. They have eFlyer. And why? Because it's quite cheap to run it. So you can charge it up for about under $5 easily. Whereas, you know, for most of the other... you can say similar aircraft like the Cessna 172, you might have to fill high octane for that or F gas, which is, you know, quite more expensive than just five pounds worth of five dollars worth of electricity. Yeah. So it makes economic sense for a lot of trainers, training schools, flight training schools to have that. also the maintenance requirement is pretty low with the engine every now and then you have to send it for servicing and overhaul etc with this one you know you can have motors flying for years without needing anything uh to be done on them right yeah it i i'm definitely seeing it take off on on skyzero .io um the website where where i track this like trainers are definitely the thing which fly the most, right? The Papistrel Velas and Alpha are hands down, like racking up more miles, kilometers, nautical miles, whatever you want to call it, than anything else right now. And to your point, I think they're really catching on. E -Flight Academy in the Netherlands flies these exclusively. Something Aviation in Fresno in California has four of these. um yeah i mean that's just that's the two off top of my head i think there's another one in pit meadows and british columbia there's a lot of different flying schools that are that are going this way yeah it's easier to also get it certified because it's just a conventional aircraft with a motor instead of an engine yep an ic engine yep Well, and to your point, H55 and BRM Aero with the Bristel Energique recently got that certified in not only EASA, but FAA2 now, if I remember right. I think Mosaic helps with that. Or they might have certified it under Part 23. I'll have to check. But yeah, you're starting, to your point, there's definitely a lot of options in that category. And I can see it growing. Yes. What stands in the way of something like aluminum air getting to the next? When you think about what's blocking us, what's holding us back, what comes to mind to you right now? I think it's just awareness. And once it has more eyeballs and people know what it is, a lot of people would just dismiss it. Oh, it doesn't recharge. I don't want to know about it. But they're overlooking the benefits of it. It's very safe. It gives you... three to four times at least more energy for the same amount of weight. You can charge it back up very, very quickly, fill it back up, whatever you want to call it. So I think once there's more awareness around it, then people will start adopting more of it. That's the only hindrance I see. Very cool. You make me want to take a swing at it for sure. So what else do you think is in the future? I mean, we've talked a bit about the present and we've talked a little bit about what's coming next and some of my favorites in terms of aluminum air and structural batteries and so on. But what do you think? What will we see in 10 years, just to pick a number out of a hat? I think we'll see a lot of hybrid aircraft. And the reason we'll see them is because they're the best of both worlds. They make use of the... efficiency that electrical propulsion offers. And also they gave you the range because of the hybrid turbo gen system. So you can have a turbo generator and Rolls -Royce is developing it. There are other companies that are developing it. I think Honda is developing their own. So the idea is to have a turbo generator. That would deliver you all the power you need. And we've seen that they've developed it till the scale of megawatts. So your normal eVTOL, like you can say vertical aerospace or Joby or Archer, they require maximum of 600 kilowatts to fly while they are hovering. So these gensets or turbine generators, sorry, they are in the megawatt scale. So they can provide not 600, but 2 ,500. So even Joby can fly with them. And the good thing about them is they're very light in terms of their power density. They deliver. the pack punch so they deliver a lot of power for electrical power for their weight so what you can you will be seeing in the near future is you we won't be having many pure battery electric aircraft yes they will have their role kind of in maybe four -seater 60 -mile category but if you want to go further like hot aerospace or aviation alice or many others then you might see the turbine generators inside these aircraft that are delivering power to electrical motors rather than engine driven ic engine driven propellers we we will certainly not replace the jet engine in the near future so Any aircraft that use jets, they're still kind of, you know, they will be unhindered by this development. But aircraft that are using small internal combustion engines, Cessna Caravans, for instance, or a smaller plane, general aviation aircraft, I see a lot of changes in the general aviation aircraft category. Got it. So that's the future because, you know, Your internal combustion engine at most can be 25 % efficient, whereas your electric motor goes up to 90, 95 % efficiency. So you're almost more than three times more efficient in energy from your internal, if you compare the internal combustion engine to... electric motor -driven propeller. Clearly. We had Ed Lovelace on the channel last month, and we were talking about just that. And we talked about sort of independent hybrids like the ES30, where you've just got independent propulsion systems. We talked about Ceres, where I think Viridian's going this way, where they're going to have a small turbo generator only if they need it for VFR reserves, or IFR reserves, I should say. And there's other, EL9, for instance, is also a series hybrid where the turbo generator charges the batteries, and the battery then drives the eight distributed propulsors, four on each wing, if I remember. But then he was talking about his Echo Caravan, where they've taken more of a parallel hybrid approach, where essentially the combustion engine is driving the propeller all the time. and they also have electric motors in there. And I think the engineering thinking going into this is to say, okay, if we can have an electric motor to provide maximum thrust at takeoff, right, when we need 100 % power, when throttle goes to 100, then your combustion engine is going to be at max RPM, and also the electric motor will be kicking in at that rate. And this allows us to use a smaller piston engine than we would have, which means that once we do pull back to, say, 70 % for cruise, then that combustion engine won't, it'll be perfectly sized for its job. It will be optimized for the cruise part. And he would go on to make the point, if I understood him correctly, that when you do a parallel hybrid or even a, no, sorry, when you do a series hybrid. You need to charge the battery and you have some small losses there. Inverters aren't perfect. And then to your point, there's a small loss between the battery and the DC motor. If it's a DC motor, small, but not much. And worse, if it's a DC battery and an AC motor, then you also have extra conversion losses. Of course, you can just avoid that mistake. But he would say that the parallel hybrid allows you to not have to worry much about that extra wasted combustion energy. But I'm with you. At the same time, clearly, electrical motors are more efficient in themselves. Clearly. There's no doubt about it. And I think the point he was trying to make is that in a two -prop or one -prop system, which the Echo Caravan is a big single prop, obviously, that the added efficiency is worthwhile. When you get into something like the EL8 or EL9, I should say, with the eight propulsors, no, go series. Because you're not going to put eight... separate combustion engines on it. It just doesn't make any sense. So it was interesting to hear you go in. So are you making the assumption that distributed propulsion then, when you're talking about series hybrids like that, or what do you think? Let's say distributed propulsion, it's obviously all electrical. So you would have, it doesn't make sense to have distributed propulsion with conventional propellers. driven by ice. Although there is one instance where that has been done. It was Howard Hughes with his epic plane back in the early days of aviation. The Spruce Goose, I think it was. Yeah, yeah, okay. So it had multiple propulsors on its wings, and he managed to achieve a liftoff, but it didn't go very far. To take the benefit of the electric motors which are really low weight and provide you massive amount of trust then you you can have either you can have a battery -based systems for that or you can have you know a battery that is backed up by an electric generator or and also one thing that is often comes in the way of a hybrid system is that is the noise that the generator will produce so it depends if you want to have a noisy aircraft or not because once the generator kicks in it will produce its own noise right because it's a turbine generator so if you have a pure electric propulsion system then yes you have no noise yeah that's the advantage for urban you definitely want something more which is battery driven if you can get it to your point yeah that's definitely true okay so this is our future you're definitely expecting more hybrids i think you're right uh i will say i'm looking forward to maybe getting to jet based hybrids down the road but that's probably there's a number of materials challenges to solve before we can do that can i ask something you're most proud of either in your career so far with ground -based vehicles, if I remember right, or with the channel? Like, yeah, what are you most proud of? I think I did a video called Batteries for Electric Propulsion. And I was contacted by the FAA. And they asked me if they could use that as training material for their program. So, yeah, I was proud about that. So I always wanted to contribute to the aviation world. It's such a passion of mine. So, you know, when they asked me that, I was really delighted over the moon about it. That's amazing. That's amazing. So, like, when you're getting onboarded there or going to a program, that's too cool. I have to mention this, though, that, you know, the FAA. is behind in this new mode of propulsion. They are more reactive than proactive. Whereas in China, we see something, you know, totally vice versa. So over there, they're helping out the regulatory body is helping out there. EV tool and electric plane manufacturers and giving them the tools and leeway they need. Whereas over here, I would say they're at least one year behind the development. So that's why certification is a challenge. And it will be for aircraft like Joby and Archer and others. that follow this route. Yeah, for sure. It seems to me that EASA and maybe UK's CAA are in the middle. They're not supporting it as much as China is. I mean, that's amazing. They're all kind of sitting on the fence with this one. And they're not really embracing this technology. Sometimes I feel that they're waiting for something bad to happen and then they'll say, oh, we want to close the chapter on this one. We don't want to go that route. I get the feeling sometimes that's the case. It may not be. But yeah, they should embrace this technology because this is the way the world will go. And, you know, with destination zero and you want to go low emissions by 2050, this is a way that provides you the way that will take you there. I think one of the things that you've done that's inspiring me the most just this moment is the solar cargo. Anything I think we can do that takes trucks off the road in terms of moving cargo around could be very impactful, right? I mean, and it may be a while before we have something that can carry 300 passengers across the Atlantic Ocean. That may be a while. But man, if we can start to take trucks off the road with something like that, that could be amazing. Yeah, one thing that is quite interesting and it's happening in the solar energy world is that the energy efficiency is climbing for solar cells. So if you remember the planet impulse, solar impulse that happened in 2015, it was an aircraft that circumnavigated the globe with just solar energy and it flew day and night. So the... Cells that were on it were about 23 % efficient. Right. The cells that are now available are about 30 % efficient. Right. Right. So straight away, you have a 7 % efficiency advantage. And they're saying with triple junction solar cells, you can go up to 40. 40 % efficiency. 40 % of the sun's energy would be converted into electricity. That means you'll have more power. The solar impulse went very slowly. It was a very slow aircraft. I think it did about 50 miles an hour, 60 miles an hour. And that was because it was so large. Its wingspan was that of 747. if you can make the aircraft more compact you have more power per unit area you can go faster and that will make the design more practical there have been many aircrafts that have used solar energy and i think there is the stratoflyer that was developed in switzerland that flew there there's the um there's the e -flyer again in usa that did coast to coast uh on solar energy yep yep solar impulse so Once you take this development in the world of solar cells on board on your plane, so you have about 40 % efficiency cells on top, you have more power at your disposal, you can make a smaller plane that goes faster, and you can use it to deliver payloads. You can have autonomous aircraft that will be doing your mid -mile logistics. Right. Right. If you don't have to carry, you know, 100 kilograms of pilot and how many kilograms of safety system and everything else. Yes, exactly. Pressurized cabin, you know, all of a sudden that can all be cargo instead. Yes, exactly. So, yeah, I think UAM and solar in combination have got a really interesting future. What about something you've learned? Is there something that you thought was true when you started this journey that you have since realized wasn't? wasn't what you thought? Any learnings like that? I had a lot of faith in many battery chemistries and that have never come to fruition. I thought that when I started the channel that lithium cell for battery, this is it. This is what we need. But again, it has got its own challenges. Although, even though it was providing like 400 watt hour per kilogram 10 years back. I think it still provides that, but it had some inherent safety and life cycle issues. The other thing is solid state batteries. So I've been hearing this, that they are just around the corner, just around the corner. And that didn't happen. A couple of disappointments that I had was with Lilium. I really like the design. Yeah. But unfortunately, I don't know what their current state is, but I don't think they're very financially stable right now. Right. If I remember right. Volocopter got acquired by the same company that owns Diamond. But I think, yeah, I don't think anything good has come for Lilium yet. There's been a couple of buyers who've come out of the woodwork, but then not done anything. So yeah. And one thing that I used to think in a certain way, but that thinking has changed. I saw a comment once on Lilium and it was that Things that have a low, very high disk loading, which Lilium had, means it had a high number of small propulsors, right? And Volocopter had that too. Several propulsors, but small disk area, you can say. Right. Any aircraft like that would consume tremendous amount of power to get off the ground. Right. He was an aeronautical engineer who had been in the field for a long time. And he said that Lilium will never take off the ground because it has some inherent design problems. And at the moment, I thought, no, you know, it will definitely because I've seen the flight happen and I've seen the test flights and, you know. So it's definitely and I wanted that person to be proven wrong. But unfortunately, it wasn't to be. Yeah. So this is conventional wisdom that he has learned over the years. Yeah. That if you have rotors that are large and they push down air slowly, you require a lot less power to get your lift. Got it. Compared to. several small propulsors. That requires too much power. Any startup, when I see any new design, now I gauge that design based on the disk area or the disk loading. And that gives you a clue if it's going to fly or not. Interesting. Cool. Cool. Okay. I will bring us into our lightning round. And so this is meant to be the same couple of questions that I ask everybody. And I asked you earlier what your favorite aircraft was, and I think that's very much, and you mentioned the Pivotal. So you can use that again if you want, but I'll ask you again. What's your favorite aircraft? Let me go back to this and see if I can find another one, another favorite of mine. The Jetson one, I really like it because Although it's just a drone with a person sitting in between. But in terms of, I feel like flying it is quite fun because it's very responsive. It's very compact. You feel like, just like in a go -kart, you feel like you're out there. So Jetson One is another favorite of mine, you can say. It's very simple. Yeah, the flight time isn't great. And safety -wise, perhaps a lot of people would say that they don't like the sight of open blades and an open cockpit. But I see that, you know, it's very responsive. They often release videos. And I think they released a recent one where they're going around obstacles. I don't think the Pivotal Helix would be able to do that. It's not very responsive. There's a delayed response with that. But Jetson One was able to do that. So in terms of pure flying fun, I would opt for Jetson One. Nice. Okay, what about a favorite airport? I really like the Schiphol Airport in Amsterdam. I think it's quite nice. I've traveled from there at least a few times. And Dubai used to be my favorite airport before that. Yeah, I was a frequent flyer. I frequently fly using Emirates, but I think it's become very pricey. So I can't afford it now. Yep. Everybody agreed with you. I'm pushing the prices up. Okay. One more, and this one is more personal to you or just your interest in general. Is there anything you want to give a shout out to? Anything you want to, maybe it's content you made that you're really happy about or excited about, or maybe it's content somebody else made that you're really loving. Any shout outs? I like Real Engineering channel. I think they do really good videos. Mustard. I really like them. But these are big channels already. They, you know, they don't want my shout out probably. But yeah, they do inspire me to make more videos. And they spend quite a lot on their graphic design. Yep. Yep. On their graphics, which I don't, you know, my, my videos are pretty grounded, I would say compared to them. But yeah, I do. Follow those channels. Yeah, no, I agree on both of those. Who's the guy that's often doing stuff about bridges? I want to say his name is Grady, and I don't think it's real engineering. He's similar to real engineering. He covers more stuff than just bridges, but I think he was a hydrological engineer, so I think that's what his sort of speciality is, is dams and bridges and this kind of thing. Yeah, I'll have to look up the title. But yeah, that's one of my favorites right now too. Well, Haroon, thank you so much for your time today. I really appreciate you making time to come on and talk to us about electrified aviation. This is great. Thanks for having me. It was a joy to speak to you. Okay. You're very knowledgeable as a host, which helps. Yeah, you're being kind. But yeah, thank you. Appreciate the company.

Ed Lovelace is a CTO and VP of Engineering at Ampere, a really interesting electrified propulsion aircraft company. You might know them from the Electric Eel, an electrified Cessna Skymaster, or from the Echo Caravan, a hybrid powertrain -based grand caravan. Ed has 30 -plus years of new product development and commercialization experience, leading tech and engineering on air, land, and sea. He led electrification technology at Aurora Flight Sciences and at Boeing Next, and he led commercial engine controls development at GE Aviation. Dr. Lovelace is a U .S. Department of Transportation Eisenhower Fellow in Transportation Research with degrees in mechanical and electrical engineering from MIT, and he's chair of the SAE E -40 Electrified Propulsion Aircraft Standards Committee. And this is the very first episode of the Sky Zero podcast. Okay, so Ed, we just read off your bio, and it talks about air, land, and sea, which I loved that part. That was a lot of fun. So yeah, I'm hoping you can tell us a little bit about yourself and your background, and I think you have to explain that. Tell me about air, land, and sea. Yeah, sure. Absolutely. I started my career working for GE Aviation, and that was where I quickly learned that Sort of the transformation to electrify lots of different things, especially in the mobility area, was really one of the key things that was grabbing me intellectually from my career. After six years with GE Aviation, working on commercial certification of jet engines, I then went on to graduate school. and a series of startups that were really all about electrification, whether it was for underwater electrified unmanned vehicles or hybrid electric and fully electric ground vehicles, both military and commercial, and also some consumer work. And then most recently, really returning back to aviation over the last eight years. Cool. Cool. You've had a heck of a journey. And so it sounds like you knew you were in the electrified path really early, too. Like, I'm almost jealous. I don't think I realized I was obsessed with that until maybe 10 years ago. So it sounds like you beat me by a bit. Yeah. So, I mean, of course, I'm aging myself here. But, you know, back in 1988, when I started with GE here in Massachusetts, like I said, I was working on controls for commercial. jet engines and it became pretty clear when I started to get involved in some of the advanced R &D activities we were starting to look at you know now that digital controls and magnetics and high voltage semiconductor switches were becoming more robust and higher reliability what were sort of the next opportunities in terms of aviation and they were all about electrification. At that stage, it was, I'd say, relatively simple stuff like using digital controls to have more complex or tuned startup sequences for the gas turbine engine, which would allow them to have a more efficient compressor design. that would install on startup. But with some of the advanced R &D groups I was working both with directly at GE Aviation and also with their global research center, we were starting to look around the corner at what's next. And one of the first electrification projects I worked on was a high temperature direct drive starter generator for a gas turbine that was being developed for a military tank. And that then led into some graduate research back at MIT. And then it was kind of off to the races after that. Cool. Awesome. Yeah. A heck of a career. So how did you end up at Ampere? Yeah. So I had been at a commercial hybrid electric truck bus and shuttle company, XL Fleet, where I had taken them from. the first two bands on the road with Coca -Cola and Pepsi to delivering at a rate of a thousand vehicles a year here in North America. And we were closing in on our D round funding. And I got a call from one of my friends at Aurora Flight Sciences about some of the new sort of bleeding edge projects they were doing in electrification. And at that point, Aurora was It was still a private company. And I said, hey, for the first half of my career, I've done a lot of one -off prototypes, bleeding edge type of technology. In this second half of my career, I'm really more focused on new product development. So how can we leverage technology that's emerging to actually get something into the marketplace? And then a few months later, Aurora got acquired by Boeing. And then I said, well, now that's kind of interesting because now you have the resources to really turn all of these great ideas into commercial products. So I ended up moving back into aviation, working for Aurora for three years until, you know, they had some of their financially challenging times and they decided to shut down the Boeing Next activity. And at that point, I had a couple of colleagues contact me that used to work at Boeing and were doing some work with Ampere. They said, hey, Ampere is looking for a new CEO. Cool. And they're developing the solution for. hybrid electric aviation. And I heard a little bit more about it. And I said, well, it sounds like exactly what I did with the hybrid electric truck company, but with wings. So I was like, nice. It's funny. I don't know if you've seen my, I'm doing an article series about, you know, electrification lessons from the automotive world. And the next one I'm tackling is all about the hybrids and how all that's going to work. So I'm really glad that we get to have this conversation now. But yeah, I keep thinking about like, it is the same. And then you're like, wait a minute. regen only while landing so you know there's enough similarities and enough differences yeah yeah and that's exactly right there there are some things that are distinctly different but there's a lot of common underpinnings yep for sure cool so your role as a company cto so yeah what would you say you guys are trying to do what's your mission there at ampere Yeah, so I do like to use our mission statement quite a bit because I do think it's quite powerful. And Amp Air's mission is to become the world's most trusted developer of practical and compelling electrified aircraft. Nice. And those have all of kind of the key words that have brought me to Amp Air and keep me excited about what we're doing day to day. Trusted. meaning something that is safe for the marketplace that we can develop with the FAA to get it commercialized and certified. Practical and compelling. Compelling being something that has meaningful advancements and benefits over the current state of the art. Something different, either enabling a new way of travel or doing something more efficiently or cost effectively. And practical. something that we can get into the marketplace this decade. And so those are all the things that drove me here. And really the key mission that our whole team is focused on is bringing the first hybrid electric aircraft to the commercial marketplace. And in our case, that launch product is going to be the hybrid electric Cessna Caravan. Delivered to the marketplace as a supplemental type certified product. Awesome. Awesome. When I think about the Grand Caravan, I think about cargo, but obviously it can do passengers too. I mean, do you know like what missions and use cases and markets you want to tackle first? Yeah, both of those. You know, cargo is definitely a pretty natural one because of the low... fuel consumption of the hybrid electric caravan. It becomes very interesting for some of the longer routes that are used on cargo applications. But we also have a number of customers in the passenger market as well, because this is something that can be dropped into any existing operator's network. with really no barriers to introduction, it becomes a solution for passenger as well. Nice. How should I think about it? Sometimes when I think about you guys, it's almost like a propulsion company, like the way Rolls -Royce sells propulsion to Boeing. But it seems like it's more than that. And your mission statement also talks about it in terms of delivering aircraft. How should I think about you guys that way? You should think about us and really a number of the companies that are in the electrified aviation space. as breaking the traditional boundaries between a traditional propulsion company and a traditional aircraft company. One of the other hats I wear is I chair the SAE E40 Electrified Propulsion Standards Committee. And at the very formation of that, everyone with expertise who came to the table was either coming from a traditional aircraft OEM, a traditional tier one propulsion supplier. And then there were these other groups that started to join that were coming from the automotive supply chain world, or maybe it was an electrified aircraft startup that was just forming. And it became pretty clear early on that a lot of the solutions companies were looking at really sort of blur that boundary right and uh you know the easy one is is the whole ev tall case where you're talking about multi -rotor systems that are not just propulsion they are flight control systems right right and and so uh when you talk about traditional gas turbine propulsion companies yes there's a high level of specialized expertise on a very complex device, which is a commercial gas turbine. And it sort of naturally created an expertise boundary and a very small set of companies that could execute that, do the manufacturing, which requires high precision lines, and do all of the inspection and maintenance and service systems that will allow that to succeed in the commercial marketplace. All of those doors have really been cracked. uh with the advent of electrified aviation uh you've got supply chain coming in from the automotive world still got to meet aviation safety standards right but you're you're when you talk about a propulsion motor an electric propulsion motor something with about 12 parts right as compared to a gas turbine Right. Which are exceedingly complex. Proof that our species is capable of very complicated things. Yeah. But that doesn't mean we should do it forever. Yeah, for sure. Right. Now, that still doesn't mean that, you know, we aren't a propulsion company. Now, the core technology that is part of our launch product is the amp drive, which is integrated parallel hybrid powertrain. And that is the core new piece that we are bringing to the marketplace as part of our first product. But what we are going to sell as a product is a complete upgrade kit. As I said, that's part of an SDC product. And we will be responsible for managing the installation, maintenance, and the support for that whole installation kit. Right. Got it. It's funny, I was watching this Sandy Munro YouTube video, and you're talking about the automotive world, so I feel like it's fair game to bring him in. He's this sort of automotive engineer that does a lot of like... electric car teardowns you know and he'll like tear apart the battery pack and be like they shouldn't have done it this way they should have done that uh and not just the battery pack he'll tear everything down but he was interviewing the folks over at harbor air about their dhc the beaver the e -beaver there yeah and you know just listening to at least for the first version obviously right this this this won't be a production version but oh well you know we've got to have an oil system for the propeller and a separate oil system for the engine and oh the engine used to do both now what are we gonna to do and so you sort of end up with a lot of like stuff in the passenger cabin that used to be didn't need it at all or it was hidden away somewhere so when when i think about you guys selling these kits like it sounds like there could be a fair amount of engineering for folks to do maybe the caravan lends itself to this in a way that i'm not getting though like how how how's that going to work yeah uh there are already hundreds of stc products for um part 23 aircraft and the caravan you know may even have the most that are available out there some of them are powertrain upgrades some of them are other aero mods or other uh interior mods so this really just fits into that very similar category got it of course for our audience that's a brand new tech the abbreviation for our audience stc Supplemental type certificate. Got it. There we go. So a normal aircraft that gets certified is a type certificated aircraft. Yep. That's when you're doing a clean sheet design. When you're just doing a modification to an existing product, it's an STC. Got it, got it, got it. Okay, so this sort of fits into that from a regulatory perspective. That's right. Yeah, cool. Still, a lot of engineering challenges to tackle. Oh yeah, so the kit is not just the powertrain. The kit is the amp drive hybrid powertrain, the amp pack high voltage lithium battery pack, high voltage distribution, some modifications to the fuel system, and some modifications to the flight deck and a new propeller. Got it. Okay, cool. So quite extensive. Nice. Yeah. Nice. Okay. Is it the eel because 337, which is of course like internet leapspeak for eel? Yes. Yes. You got it. Okay. But, uh, you know, as many sort of double meanings as we can, uh, jam in there, we will. So, you know, an eel is also a, uh, potentially an electric animal. So, you know, that's another potential meaning of it. But yes, you got the 337. Nice, nice. OK, cool. So I'm assuming that that one was like a market test, you know, something that, you know, give it a proving ground. But it wasn't necessarily meant to go to production. That's exactly right. So, yeah, for your audience, we have three experimental aircraft that we're flying right now. We have two hybrid electric Skymasters and one. hybrid electric caravan. As you just pointed out, the Skymasters, our current intention is that those are used for market development and as a test bed for advanced technology. For those unfamiliar with the Skymaster, it's two -prop inline push -pull configuration. It's honestly ideal as a flying test bed. because um the configuration of that hybrid is a little bit different than the caravan so the caravan is like you know a classic integrated parallel unit that that might be in a prius or any plug -in hybrid electric vehicle nominally driving one of the axles in your car right um the skymaster which has a prop in the front and a prop in the back along the center body of the aircraft We configure that as what we call a independent parallel system. Right, right. So the analogy to a car is if you had a gas engine driving one axle and an electric motor driving the other axle. Right. The advantage, though, is we can test out some of our new technology on the electric prop system of the Skymaster. And if it shuts off during flight, we still have symmetric thrust. Because the gas powered engine is still in line center in the aircraft. Right. And you still have plenty of power for safety of flight. Right. You don't have to suddenly like yaw the plane considerably in order to go straight. Yeah. And if you look at some of the flying test beds that are being developed for larger aircraft, you know, they either have to substitute one of the winged engines for the experimental engine. Or if you go all the way up to transport class, sometimes they have a... a pylon sticking out of the side of the fuselage. Right, right, right, right. Yeah. Well, I'm thinking the Zero Avia did that with the hydrogen on one side and the original, I think it was a Pratt & Whitney on the other. But to your point, yeah. I mean, like when Boeing does this, it'll be a pylon. Yes. Yep. It'll be just sticking out the side. Yeah. Well, and of course, the other that comes to mind is Volt Aero with their Casio One, also using the Skymaster. I think they put gas in the back and electric on the two pylons. On our two Skymasters, in one of... them the electric prop is in the front and the other the electric prop is in the back oh okay uh the only the major reason for that is is just for center of gravity because in one of those aircraft uh the one we use for market survey that we call our hawaii bird the battery is located in a cargo pod below the fuselage So with that forward weight, we want the heavier gas engine in the back. Got it. Okay. In the other one, the ARPE Bird, which we use, again, for R &D purposes, in that one, we've made the battery pack more accessible in the rear of the main cabin. And so then in that case, we put the heavier gas engine in the front. Got it. So what kind of challenges have you faced? I mean, I mentioned a couple of guesses that I've got, but like when you think back about the challenges you faced and what learning curves you guys have had to climb, like what comes up for you? Yeah, I mean, there are a lot of the typical things that are small business challenges. which is really deciding what's the most urgent and important investments we need to make and being able to break down our project into incremental milestones where we can hit a successful point before moving on to the next one. So really structuring our programs in that way that we can sort of sequentially start with commercial off -shelf equipment and move to modified commercial equipment. then finally move to the Amp Air custom equipment that's more towards commercial intent. So really structuring those programs has been a bit of a Rubik's Cube effort over the years. But I think overall, we've done pretty well with that. We do have some worldwide supply chain. So the other challenges we face are really mundane things like metric parts and fittings and making sure that we have a compatible supply chain. Right, right. Oh, gosh. Wow. Okay. Yeah, I can only imagine that's a fair number of design challenges there for sure. Sorry, I don't mean to drag us back to the hybrid propulsion, but I've got a couple more questions there. So the assumption I make when you talk about the parallel hybrid propulsion, I'm imagining that we're using both during takeoff, right? And I come to this from a software background, and I'm learning as much as I can about aviation as I go. The assumption I make is that means that we can have a somewhat smaller sized piston in order to use less power. And hopefully that helps with like cruise efficiency. But I don't know, like help me out with understanding that better. Yeah, you're exactly right. So there's a few ways you can configure a hybrid in terms of its operational scenario. You can do what you just said, which is exactly the way the caravan. is planned to operate uh you use blended propulsion for 100 power on takeoff and climb and then when a pilot pulls the throttle back to cruise uh you're running at a high efficiency point for the downsized uh jet a engine that's part of the hybrid power plant yep and that's how you really eliminate the payload range challenges that you have with with an all -electric is by using uh a jet a power plant uh that's very efficient for um the the main range operation yep now you the other way you can architect a hybrid of course which has been done in some ground vehicles is as a range extender so the difference there is that your electrification portion so your your electric traction motor has got to be fully rated sufficiently to run all electric for all of your peak and average events. You also, if you're running this as a range extender, you are typically putting in a larger battery and then using gas for just longer trips. So that's the classic example there is your Chevy Volt. Right, right. Chevy Volt, the BMW i3, the sort of REX range extenders. Yeah. Yeah. Cool. I will tell you this. So I worked in that sector for such a long time and had a chance to meet a lot of executives in Detroit who had tried out our hybrid electric commercial product. And I can tell you from talking to some of them, they all know that for most use cases, A hybrid designed for blended propulsion is the more efficient solution from an energy use standpoint. Use battery for what it's good for, for the peak power events. Use a gas burning engine for what it's best at, which is constant rated power capability. But the challenge in the automotive industry is the sales challenge. Right. And the consumer market. really wanted all electric range. So a lot of those vehicles got architected so they could have. small electric range. Well, and when I think about like the i3 and the Volt, I think the Volt cheated a little bit and used parallel at high speeds, like over 70 mile an hour or something. But other than that, yes, it was serious. But I think of it as like a tipping point where did batteries get to a certain specific energy or volume? Well, it was probably by volume when the automotive weight is not as important an automotive as it is in aviation. But I wonder if there was like a tipping point where all of a sudden it was like, okay, we can do 200 miles, you know, and the Model S comes out. And like, I was looking back over the history and the Model S came out sort of like shortly after the i3 Rex. And it was almost like, oh, you could have just done it that way, you know, but you probably couldn't have until you could, right? So do you see like a tipping point moment like that for aviation? Do we need like 600 amp hours per kilogram? Like, what do we need to hit that? So it's a very interesting topic and one that I talk about quite a bit in some of the public events that I speak at. I was just speaking at a battery seminar this summer where I went through exactly the trade -off that you're talking about. The mountain to climb for aviation is much bigger and it has some different constraints. But you're exactly right. In the automotive sector, once... We hit the point where we could get 300 miles range in most environmental conditions in a decent sized car that had less than a $10 ,000 premium. That was really kind of the tipping point. The one remaining challenge for automotive, of course, is the refuel time or the turnaround time. For the vast majority of trips, though. 300 miles or a little bit less in cold weather is a non -issue and you can charge overnight sufficiently to have a ready car the next day. So it's a fantastic solution for that. Charging is getting better. My Ioniq 5 charges in like 18 minutes, but they don't all do that. So that's fair. I hear you. And that becomes more of an infrastructure barrier unless you're doing it at home. True enough. Yeah. To your point, I know not everybody that's doing parallel electrics is thinking about doing charging. Maybe there's, you know, some would argue, I think Horizon is not planning on doing it at all, which makes sense. I mean, where do you guys sit on this? I mean, should I think of it like the mild hybrid, the early Prius, or is this like a plug -in hybrid? How should I think about that part? So it has some characteristics of a Prius, and it has some characteristics of a charge -depleting plug -in hybrid. So like a Prius, we use electric power and the energy from the battery for the peak power events. So all of the humps, which in a flight are primarily at the beginning on takeoff and climb, are served by the energy from the battery. So in that way, it's like a Prius. The way it's like a plug -in hybrid is it is charge depleted. So during that takeoff and climb, you are depleting the battery down to a lower state of charge. Now, like a plug -in hybrid, and most people either aren't aware of it or don't use it, in most plug -in hybrids, there's a switch in the center console where you can set it to triple charge your battery when you're on the highway. Right. And what happens there is you're putting out a little bit more power from the gas engine and operating the electric machine as a generator to trickle charge the battery so that when you're at the end of your trip, you've got a full battery. So that's exactly the way we've architected a hybrid caravan. And that's why there are no barriers for deployment in an existing aircraft fleet. They don't need to wait. for charging stations to be implemented at an airport. They can put this anywhere in their cargo or passenger fleet and it has more range. than the conventional aircraft that they're currently operating. Yep. I want to thank you for not saying it's infrastructure. You're not infrastructure dependent. I've heard people use that term, meaning you don't have to install a charger. And I get it. It's slightly more complicated than that. Your airport might need to upgrade to a larger electrical connection. It's more than just a charger. But when I hear people put it that way, it almost feels like they're... trying to suggest that it'll never make sense, which, I don't know, it just seems short -sighted. So thank you for not putting it that way. I'm glad. No, but just think, if you've got, you know, a fleet of these aircraft operating at a regional airport and they're successfully taking a lot of the passenger load, now the airport and the either public or private organization that owns that airport has more incentive to start investing in infrastructure to grow there. That's right. Otherwise, you're asking them to take a gamble before the aircraft come that they should spend the money on putting infrastructure in. Yep. So it's funny. I was talking to a cousin the other day who flies for British Airways. I think he's flying like 321 XLRs or something. And I got to talking to him and thinking about like, yeah, well, we're probably going to see like hybrid dual aisles and single aisles. And at some point I realized, wait a minute. Kyle, you're inferring that you would hybrid a jet engine. And I started to look it up. I guess NASA has a high -tech program, H -Y -T -E -C, where they're looking at doing just that. But dealing with the heat coming off of a proper jet turbine instead of just a piston engine, to your point, all that automotive goodness comes in. Because it's a piston engine, I assume. Have you looked at the other side of it, like being able to do hybrid with jets? What's your take? I mean, is that going to be a thing? I think that's definitely going to be a thing. And I was just at NASA actually a couple of times over the summer. discussing some of the electrified propulsion projects that they've been supporting over the last years. While some of the bigger investments have been towards Part 25, so the transport class aircraft, one of the points that I was stressing is that, yes, eventually this is all going to make its way to multi -megawatt gas turbine. powered aircraft. We really have to have a portfolio approach right now and help get these Park 23 aircraft into the marketplace because everything that we are commercializing for Park 23, the electric machinery, the power electronics, the control systems, the high voltage batteries, those are all going to be relevant. for the larger aircraft in larger scale, of course. Right. I just think about them as being very hot places. I suppose a piston engine is too, but it just seems like it's inherently more difficult. I think the NASA page literally had a picture of an engineer like... I don't know, with a blowtorch or something, like raising a, you know, a plate that was meant to be like not a cooling plate, but, you know, in order to protect like a firewall. And they were raising it to like 3000 C or something. And I'm like, yeah, that seems like that's the kind of challenge we're going to have to solve to do this. Yeah. Well, the reason I'm smiling a bit about that is I worked on exactly those kinds of projects in the first half of my career when I was doing, you know, bleeding edge prototype work. I had several projects working on. completely oil -free gas turbine system for unmanned aircraft. So that used a combination of magnetic and air bearings with embedded starter generators that were capable of operating at over a thousand degrees C. And yes, we made a lot of sort of incremental component level advancements in that area. All of those things largely driven by material limits. They've still got a ways to go before you're going to see them in any kind of commercial horizon. But it's there. The ideas are there. The proof of concept prototypes. Uh, some of them have been, have been executed. Cool. Cool, cool, cool. Okay. So that is one of our possibilities way forward. What else do you, I mean, SAF, people talk about it a lot and I expect it's probably part of the solution too, but, but nevermind what I think, what do you, where do you think the industry's going? Like, what are we, what are we going to see in 10 years? Yeah. So I tend to think about, uh, not, not focusing on maybe one thing that, that is going to win, going to be. marketplaces for a number of different solutions. You know, SAF has a scale issue right now and a feedstock issue right now. So it needs to be green SAF, needs to get to scale, needs to get to a price point that makes sense. But as an example, if you compare it to hydrogen, it likely has fewer miracles that need to happen than hydrogen does. Don't get me wrong. I'm not saying abandon hydrogen. I'm a big believer in continuing to fund R &D in that activity. But it's got some big challenges to get to commercial scale and commercial price point and be a green solution. The way Amp Air looks at that is we're ready for all fuel sources. Our hybrid powertrain, we've already tested with 100 % SAF. So when SAF does get to that scale, we'll be ready. A lot of the electrification platform equipment we're going to be commercializing can tie into a high voltage bus supplied by a fuel cell. So when that's available and it makes sense, we'll be ready for that. Now, what do I think the time horizon is for each of these things? I usually try to flip that question as well and say it's not so much a time horizon as it is a funding horizon. These are going to take some pretty massive investments in terms of dollars to get to scale and a price point where the major airlines are going to adopt it en masse rather than... demonstration projects. It seems to me that when I think about scaling and SAF, I mean, to your point about feedstock, there's not enough cooking oil in the world to power our current appetite for international travel. That's not how this is going to go. I read something the other day about Wizz Air buying up biological waste. So I think poop is the right word. And maybe that's a feedstock, you know, and as a species and as a set of species, we do create a lot of that. So maybe, maybe, apologies for the scatological references there, but, you know, it might be a solution. But yeah, I mean, when I think about the hydrogen side, it does seem like hydrogen's one party trick is that it carries more energy per kilogram than even jet fuel does. But its kryptonite is that it's tiny, and it wants to leak out of everything, and it really does not like to be compressed into any sort of reasonable amount of space. I think I did the math the other day, and I'm not an aviation engineer. I'm not even a mechanical engineer. But what would it take to... to even like a reasonable amount of hydrogen would be like an eight meter circular tank or something like this to do like a 737 across the ocean. You know, I'm not asking you to literally do the math, but is that sort of scale? Where would you put that? How am I going to get to the bathroom if there's this eight meter giant sphere in the middle of this aircraft? Can't put it in the back because when it empties, the airplane's going to tip. So I don't, I'm not, it does seem like there's some tough challenges out there, but. Yeah, you do need a reimagined aircraft design for some of these larger transport class aircraft. But as you say, its energy content per weight is great. It does have a volume problem. Depending on whether you're using liquid or gaseous hydrogen, you're still talking about a 3x to 6x volume or more issue. So you do have to reimagine how an aircraft is designed. You know, if you're stuck with sticking with tube and wing, then you're going to be using a portion of the main fuselage or extending it along an underbelly, maybe some of the cargo area, or you're doing pods on the wings. These are your avenues if you stick with tube and wing. Now, if you go to some of the more blended wing designs, then you have other opportunities for how to house it. But it's a volume challenge for sure. I guess spherical tank is probably out of the running as well at that rate. But yeah, well, maybe several smaller ones. I don't know if anyone is trying that. Yeah, yeah. That's a fair point. Maybe that's a straw figure argument. Yeah. Okay, cool. But I do want to go back to a question you asked probably 30 minutes ago. but that I didn't end up answering, which is, you know, is hybrid transitory? Are we going to get battery electric? We talked about how we hit the tipping point for ground vehicles, but the tipping point for aviation is much more significant. You know, whereas you said, and I agree, ground vehicles, they really had a volume issue. They needed to get 300 miles range in a skateboard format. Once they got there, And the price made sense. It was good. Aviation has a significant weight challenge. Today, today's, you know, let's call it Tesla Model S density of batteries. You are in the call it 200 to 250 watt hours per kilo range. At that case, you are about 20 to 25 to one. even including the differences in powertrain efficiency compared to jet A. Let's say you get all the way up to the RPE target of a thousand watt hours per kilo. If you get there, you've improved it by a factor of up to five, or you've taken a 25 to one down to a five to one. You've still got a five to one weight difference compared to jet A. So hybrid is going to be in aviation. not as some kind of short -term transitory solution, but it's going to be here for decades. And eventually it'll be a hybrid with SAF, but for now it's going to be hybrid with Jetta. Yep. Yeah, I'm with you. Well, and I think that's why I'm looking forward towards the, you know, electrified, you know, jet engines. You know, if we're going to imagine a double aisle anytime soon, like, or maybe I'm just counting pistons. Like, do you think it's right to make that leap towards electrified jets to get to like your... A380 or even the 320? There are some interesting reimaginings of how the propulsion system is architected that can get you into somewhat larger aircraft. But if you're talking 737, then yes, you're going to be talking a very efficient gas turbine that's enhanced with electrification. As you've seen, there's a number of companies have put out vision vehicles with distributed electric propulsion along the wing. That could still be part of a transport class hybrid electric solution where you have a gas turbine power plant in the center tail section that is supplementing the battery pack to drive. the distributed electric propulsors fair point i'm i'm like insisting that it be parallel when that need not be true to you to the point you made earlier on independent like a heart aerospace very much independent you know i think they're looking at pt -6s plus like electric uh in addition to the pratt and whitney's there um right so okay or or electra era with the the wind blown wing uh for for your lift power there right so okay yeah there's there's a trade -off though when you do that So I'm pretty agnostic. There's applications where series works, where integrated parallel is the right solution, or where independent parallel is the right solution. It sort of depends what some of your constraints or objectives are. But the one thing you have to remember when you do go to a series hybrid electric is that you've got a number of efficiency hits between the jet A source and the propulsion end. When you go series hybrid electric, you've got the thermal efficiency of your power plant. Then you've got an electric machine and a piece of power electronics to get to the high voltage DC distribution. And another piece of power electronics, then another electric machine. And all of that impacts your fuel economy from the jet A source. I'd argue the biggest one is the engine. But yes, you're right. Inverters are not like 90 % is maybe as much as you're going to get. To your point, you've got to put it in a battery, take it back out of battery. Yeah, I'm with you. So we tend to think once you're beyond an aircraft design that is using more than four propulsors, then going series makes sense. Well, but I think by going independent, I'm avoiding the series versus parallel dichotomy. I mean, that's one tradeoff, right, is to go from that to series. But like what Hart's doing is like literally just saying, OK, we're going to be all electric, but we're also going to put two more props on the thing that are powered entirely by a jet turbine, you know, a turbo prop. And they're not bothering with like, it's like you said earlier with the independent hybrid, you know, instead of parallel or series, independent allows all sorts of different configurations. Yeah. One of the advantages that solution has is a regulatory one. um because you have a certified thermal engine yep you don't have to touch that when you're doing the independent parallel yeah um it has it does have some other operational challenges that you need to get around but you know, these are all trade -offs. One more place I want to go is into certification. I'm glad you mentioned it. I mean, I don't want to like, where are you in terms of your timelines? I don't mean that. I mean, if you want to share, go ahead. But I think more interestingly is like, what have you learned through the certification process? It's designed to learn, I assume, you know, for you guys and for the regulatory body. What kind of learnings have come out of that? The certification is the common challenge that all of the electrified aviation aviation companies have. This is also something I talk about at events quite often. Currently, the market size is zero. I'm not so worried about another company taking all of the market share today. But the thing that we all have in common is getting through the certification process. And again, for those of the listeners who are unfamiliar with it, the regulations for aircraft certification. really didn't imagine electrified propulsion. Fuel cells, hybrid electric, fully electric, that's not written into the regulations anywhere. In fact, if you look through the regulations in detail, you can see places where gas turbine regulations have been stitched on top of reciprocating engine regulations over the decades right uh the regulations have really grown organically with the industry different different aircraft have been uh proposed for the market so the point though is uh the way all of the companies who are trying to go through the get certified and go through the process dealing with this is the FAA has a method, which is the special conditions, where any topic that is relevant for a design type cert that is not covered by the existing regulations, it's handled in a special condition. That is a negotiation between the applicant and the FAA. Once there's agreement there, that special condition topic is published in the Federal Register. There's a public comment period. And then the FAA comes back with responses to all of the public comments. And then you have a final special condition. Every company that's going to get to the finish line is likely going to have to go through that process. Now, like I said, it's applicant by applicant, but you do start to see some convergence on some of the topics now that a few companies have at least gone through that process for their power plants, if not for their aircraft. Okay, right. So if I read you right, you're saying these SCs, sorry, one more time, special condition, which does get abbreviated as SC. Yeah. So these, you didn't abbreviate it, I did, because I was having trouble remembering. But so to your point, those are sort of OEM by OEM. Like if you get one, somebody else can't use it. But I guess you could read it and make guesses that that would get approved if they wrote it similarly, I guess. That's, that's exactly right. And if you look at the fully electric power plants that have gone through the part 33 engine special condition process, uh, that is includes magnets and beta and saffron. Yep. You can see over time, there's a pretty close convergence. Uh, magnets was first, um, quite a bit of changes. Um, in the detailed language by the time you get to beta and saffron, but betas and saffrons are virtually identical. Okay. Interesting. Right. Sort of do it this way, guys. It'll be a little bit faster to go through. Yeah. The FAA is generally open to alternative proposals, but you just have to defend it and justify it. Right, right, right, right. And if it's worth it, I mean, I suppose you go to the extra effort in the end. Yep. Okay, cool. That has been a learning experience for our team. As it turns out, and this was definitely not a plan in my career, this has ended up being the third regulatory environment that I've worked through. Again, with ground vehicles working with CARB and the EPA, convincing them that a hybrid electric upgrade kit for a Ford or GM commercial vehicle was not disturbing the calibration of that gas engine that was part of the original vehicle. That was an interesting challenge with CARB that we successfully got through. And in addition to that, I also in another part of my career was working in renewable power. So I got to work with the Federal Energy Regulatory Commission. and all of the stovepipe agencies that are concerned with environmental impacts. So going through a regulatory process is very much of a learning experience. Every time. And you've signed up for it three times now. Like I said, unintentionally. But I developed an expertise in negotiating in a regulatory process. Yeah, right. Nobody grows up hoping that they get to do that. But hey, you're doing great work to do it, and we thank you very much for continuing to make progress. We're all chipping away at this thing, and we thank you for your role. That's awesome. Cool. So one more sort of a closing question, and then I want to do a small lightning round that I did not warn you about. Okay. But before we get to that, so when you think back to where Ampere's been and your role in it, what are you most... optimistic about? What are you most proud of? Oh, I mean, it's the thing I am really most proud of is the capital efficiency. I have worked in a CTO and BPF engineering at a few startups. And one of the common themes in all of them has been a real high degree of capital efficiency, meaning making a lot of progress with. modest amount of capital associated with it. And if you think about all of the things that Ampere has achieved and has been shared in the press over the years, you would think we're a larger company than we are today. But we are a pretty tight company that focuses on the tasks and the spending that needs to happen now and doing everything sort of in sequential order. So we're pretty proud and optimistic about about that strategy that we've taken. In terms of other things that I'm really optimistic about, it's been really sort of heartening to see the industry shift over the last two to three years to come around to hybrids. If you looked four or five years ago, Ampere was one of the few companies saying... We're going to launch with a hybrid electric aircraft. That has shifted over the last four years and really accelerated even over the last 12 to 24 months. If you look at everything that's going on with the Department of Defense, even they have now taken up the mantle of, yes, we've made a lot of progress in all electric. We're now going to shift gears. focus on hybrid solutions. So I'm pretty optimistic that everyone is starting to really see the market potential and opportunity with hybrids. I have to say I'm with you. I think you're looking pretty prescient at the moment. It makes me wonder whose crystal ball you were borrowing back then, because yours is pretty good, obviously. Yeah, no, it's funny. I met you, obviously, or saw you present, I should say, at the Vertical Takeoff and Landing Societies. They did an electric aircraft symposium. Yeah, the Oshkosh symposium. That's right, just before Oshkosh there, which was great. It was my first time at Oshkosh, so it was really, really eye -opening and amazing. But you're right. I mean, if I think back sort of like three -ish years ago, four years ago, like you're talking about, it was like, oh, the ES -19 is going to be all electric. Now it's the ES -30 and it's not, it's a hybrid. And I think maybe the Viridian micro liner is like one of the last stalwarts. But even they're looking at going to a series configuration at this point for sort of the extra 10 % you'll need for flight rules. But so yeah, I mean, Voltero though, Horizon, a lot of these players are definitely going the hybrid route. And not even in the series sort of range extended way, but in the parallel configuration. So yeah, you guys are looking like you saw the... future right now. Yep. Very cool. Okay. So lightning round. Um, question number one, what is your favorite airport? Oh, uh, lightning round. Oh, long beach. Yeah. How come? Yeah. Oh, uh, I remember when jet blue used to fly out of there and I had to visit the West coast for meetings. It takes like 10 minutes to get from your car to the plane. in an airport like Long Beach. Nice. And, of course, you can't argue with the weather there. So walking through the airport, it's like half indoors, half outdoors. Well, and I think of that as Ampere as like home base, too. You guys are often between Long Beach and Camarillo. It is now. So we just moved there a year ago. Yeah. But I would say my love of Long Beach goes back more like 15 or 20 years. Got it. Okay, second lightning round. What's your favorite aircraft? Oh, I'm going to say the 787. Yeah? Yeah. Awfully comfortable to fly on, for sure. Lots of balances, too. And that is the more electric aircraft in the transport category. Fair enough. It's got about 1 .4 megawatts of electrification in it. No way. I didn't realize it was that much. Wow. Huh. Cool. Cool, Ed. Well, listen, thank you very much for being on the show today. We really appreciate you. And yeah, this has been great. Likewise. Thank you for having me.

Hey, I'm Kyle. I'm the founder at SkyZero. I'm super excited about electric aviation, and I'm excited to dive into it deep. Thank you for listening to the SkyZero .io podcast. We have interviews lined up with some of the most interesting people in electric aviation. We'll go in -depth on the technology, the capabilities, the machines, and the plans that are making headlines and making waves. Our first episode is an interview with Ed Lovelace, the CTO of Ampere. The first season's interviews will all relate to an article series titled Lessons Aviation Should and Shouldn't Take from EVs. The first two articles on batteries and another one on charging are already online. You can check those out now at skyzero .substack .com. We'll put links in the description. The next article series is on hybrid powertrains, and the conversation with Ed was super timely. After that, we'll do articles on hydrogen, but there's a lot to unpack, and also on vehicle platforms. SkyZero .io is the source for intelligence on electrified aviation. Make sure to subscribe to the podcast so we can drop it in your feed.