Podcast: AIAA’s SciTech Forum Teases Hydrogen Cycles And Gulled Wings

Graham Warwick:

Hello and welcome to Aviation Week's Check 6 podcast for this week. I'm Graham Warwick, executive editor for technology at Aviation Week, and I'm joined by my esteemed colleague Guy Norris, senior editor.

Last week we were both in Orlando for the annual AIAA - American Institute of Aeronautics and Astronautics - SciTech Forum. Now for Guy and I this is a big event. Every year it kicks off our year and it's the sort of premier gathering of aerospace technologists. So we get our notebooks full of stuff that we are then sort of raring to write about as the year goes through. And it's a great event. They know us well and we know them well. And this year particularly was a very large event and appeared to be a very successful event. And we actually will have a chat with the new CEO of AIAA, Clay Mowry, later in this podcast about the event and the organization's plans. Meanwhile, I'm going to hand over to Guy who's going to paint us a picture of this year's event.

Guy Norris:

Thanks, Graham. Yes, and as you rightly say, it's a broad brush, sort of a shop window really for what to expect for the year in terms of technology. And this time was no exception. I mean, I know you had some really interesting sessions that you went to. Just to give you a flavor of what I saw. One of the things, of course was more updates on hypersonics from across the board. And it was interesting this time because I think what we really saw was a lot more emphasis on hard science, breakthrough basic fundamental research again, but also the development of a lot of actual demonstrators. So following in really the footsteps, I suppose, or the wake of the Stratolaunch Talon, which we think made a successful debut last year. There's a lot of emergence of a lot of these things. For example, Lockheed Martin Australia is working with the Australian universities basically on a common test vehicle that experimenters can use to try various experiments over Mach 5.

And then, of course, the other thing that I found fascinating was the re-emergence really of a lot of nuclear propulsion discussion. Now, obviously, nuclear propulsion for space is relatively coming back into the discussion with the NASA/DARPA DRACO program. There was some talk about that, but this was much more sort of assuming that that was going to get on the road and actually begin to show some positive developments and what could come next. And people basically are kind of excited about the fact that finally, after 60-70 years, this is potentially a real thing.

But what was really interesting, to me anyway, was that there was a discussion about use of nuclear power in the atmosphere for atmospheric propulsion. And I can see you laughing. I know I can hear everybody laughing, but with the potential for small fusion reactors, this is something that of course Lockheed came out with 10 years ago when we broke the news about the small compact fusion reactor that they were looking at in Skunk Works.

As always, these things are more difficult than anybody could conceive really. But I think there was a genuine discussion there of, yes, this is a long-term thing, but we think it could be possible. So we're going to have stories coming out about this. I almost feel like, I don't want to spoil a surprise, but one of them was a hypersonic design from Boeing, which said "If you could develop this compact fusion system, it would be the ideal solution for longer range propulsion."

Another thing that I really found fascinating was a gulled wing airliner design that a NASA study came out with. I mean, the inevitable fact about the next new airliner is that whatever engine it's going to have, whether it's an open fan, an open rotor or a ducted engine, it's going to require a lot of ground clearance for that because the sheer diameter. You're talking about wide bodied engines on a single aisle airplane.

So how do you do that? And of course, Boeing with the X-66 is looking at a high wing, so that wouldn't be potentially so much of an issue. But Airbus certainly has hinted that a gull wing, one which has got an increased dihedral angle at the inboard section, would be the best way to fit that under the wing. So interestingly, the discussion about the NASA design that came out showed that this was definitely a viable option. And there was some really interesting side aspects to that.

One is that their study actually showed that the gull wing, which everybody assumes is structurally more heavy and more complicated to build, actually may be slightly lighter. But they have to go back and do more research to understand that, see why that could be the case. But I suppose the one thing, and I didn't actually put this in the story weirdly enough, is that no matter what happens, you're looking at probably having to have a T-tail in the future, which I think is kind of an interesting fallout of all these designs. Whether you put these big engines at the tail or on the wing, you're going to have to have a T-tail. The high wing option that necessarily would have to give you a T-tail, I think because of the wash. And the rotor wash, even from a gull wing, would mean again a T-tail. We've seen pretty well the designs from Boeing and Airbus that dominate today, the A320 and the 737. But I think we're looking at the return of the T-tail one way or another.

Graham Warwick:

This is a call to any BAC One-Eleven. De Havilland Trident or Vickers VC10 engineers that are still alive out there. There's a job for you coming in. They were the last T-tail airliners, weren't they, that trio?

Guy Norris:

Well, don't forget the MD series.

Graham Warwick:

Oh, well that was American. Who cares about that?

Guy Norris:

Yeah, of course the T-tail families are out there today. I wouldn't say a dying breed, but they're pretty restricted and certainly when it comes to the big narrowbodies, these last surviving 717s, MD-90s or perhaps the last of those interesting series. And I do remember Phil Condit of all people saying, "Boeing will never do another T-tail. They're just too awkward." So maybe things are changing, but I think propulsion as always is driving the future like that.

Graham Warwick:

That's a great segue because one of the things that has become good for us, this is very much our view of SciTech. They've got very good at doing focused sessions where they bring together multiple papers, multiple presentations around a theme, and they do many, many of these now over the week at SciTech. The European Clean Aviation program has taken great advantage of that. And it's a great forum for the Europeans to present their programs to US audience, including us. And of course the Clean Aviation program at the moment, which is the big European program, is very, very heavily propulsion focused. So we did get some great updates on where they are with their plans to test both hybrid-electric regional engines and single-aisle engines, which will have some degree of hybridization in them.

One of the things I saw, and we are seeing it across the industry at the moment, was this kind of shift to hybrid as being the way to get to electrification. We knew that it was always going to be the way to electrification because batteries are not where they need to be, but people were kind of resisting it because it says complicated. You sit through any of these presentations that involve hybrid propulsion and your head almost explodes because it's so complicated how you get the energy to move around, changing it from one form to the other, managing it, moving it between one propulsor and another or something like that. But it's definitely coming.

So I think one of the highlights for me was AIAA did something unusual this year. They had a couple of keynotes in some of the sort of side sessions where they had guys from Electra, John Langford and Chris Courtin, who basically talked about the testing of their hybrid electric, extreme STOL testbed aircraft. Very interesting, great video. This thing takes off on an absolute postage stamp.

But the highlight was Kyle Clark, who's the founder and CEO of BETA Technologies. He's a former hockey player. So he's a very imposing figure, very dynamic figure, very open and honest figure. And he just did an incredible briefing on where BETA is including showing video. They have a thing called Alia in development at the moment, which is their eCTOL and eVTOL. Before that, they did a kind one-off eVTOL, one of the very first eVTOLs to fly and probably one of the very first to be flown by a pilot. And he showed some video of this thing flying and it was just extraordinary what he was able to do with this kind of one-off. But he said he learned a lot of lessons about how not to do an eVTOL by building this, but it led directly to the Alia and that was a great presentation.

And so most of my time was spent there. But also we know that across the conference that NASA was briefing on progress with X-59, which has still yet to fly, but is moving through its ground testing, getting ready to begin flying and then do its low-boom testing. And they give some briefings on SUSAN, which is an internal study into a sort of hybrid-electric aircraft design that combines both what they call these letterbox-type ducted fans in the wing and a tail thruster. So they're continuing to think about this. And we're beginning to see the first signs of NASA beginning to explore the hydrogen space. Europeans are quite far forward, but the US is beginning to take a look.

We got great insight into Pratt & Whitney's HySIITE hydrogen cycle engine, which Guy will be writing about. I mean if you want to blow your head apart, try and understand the cycle of HySIITE. But it is fascinating what they can do. And similarly, there was an absolutely brilliant presentation from Airbus on ASCEND and Cryoprop, which are their superconducting electric demonstration programs. In ASCEND they demonstrated a big benefit from using liquid hydrogen to cool the electrics in an airplane and reduce the resistance, improve the efficiency, and they really were surprised how well it worked. They're now moving to essentially an engine-like demonstrator and the Cryoprop project, and they want to show that they can get those benefits on a more representative sort of engine-type architecture. But they're very, very excited about it and they're looking at, by the end of 2030, maybe being in a position to put this on an airplane and fly it. So again, propulsion hugely important to this conference.

Guy Norris:

Yeah, and I'm glad you mentioned HySIITE. The fact that that is now being explained really, or at least they're trying to explain it to us to try and figure out how on earth you integrate hydrogen into a propulsion system that essentially could be packaged to fly on today's aircraft within the nacelle outline. And thank you for no pressure there, trying to put that out as a comprehensible story. But anyway, that's to come shortly.

So of course we also did have a chance to actually, as you mentioned earlier, to speak with Clay Mowry, and of course he's brand new into the job. Well, a hundred days as he'll explain, but of course, as many listeners know, Clay is a space industry veteran. He continues to serve as President of the International Astronautical Federation. And over his career, he's worked for various companies ranging from Arianespace to Voyager Space and Blue Origin. Anyway, this is what he had to say.

Clay Mowry:

I'm super proud of about a hundred days on the job now with AIAA. This is my first SciTech event, and it's a treasure, it's kind of like a secret formula we got down here. This is our largest SciTech ever. This morning, the last number I saw was 6,123 people registered to attend this event. We have almost 3,000 technical papers that are being presented at this event, which is a huge... When you start actually thinking about the number of people that are here and the number of technical papers, and then that all goes back and ends up in our technical library for our journals and publications. So that's really kind of our flywheel for AIAA, is getting all that really cutting-edge technical content, putting it into our library, and then having that as a resource for all of our engineers as they're designing and developing new capabilities and technologies.

About 2,000 of the attendees out of the 6,000 are students, which is also really impressive. People ask me, "Why is this event in the beginning of January? You're really kicking right off after the new year." Well, it's because a lot of the students are still on break. They haven't gone back to university. We're able to get the professors and university students here, so it's an optimal time for them to come and present papers. So you got a ton of people here from universities all over the world. And the other thing that's kind of secret about SciTech is we get huge delegations, international delegations that come here to present. The DLR for instance, the German Aerospace Center, sends about 50 of their top engineers to come here and present and learn. So it's a really interesting time for us. I would say just broadly, and by the way, this is both... We have both the aeronautics and the astronautics community here, so whatever you want to call that, we're ecumenical and we're welcoming both sides of the house of AIAA.

Guy Norris:

And Graham, you also asked how well AIAA was doing in its efforts to appeal to a wider multi-disciplinary audience.

Clay Mowry:

It's a great question. We spent a lot of time thinking about this in my first hundred days, this issue that you're talking about, which is cross-cutting content, again and again and again. And it's really a struggle for us in terms of how, I'm not going to say struggle, a challenge in terms of how we organize ourselves because we have 71 technical committees here, and each one of those technical committees has a specific area of focus. So it's very hard. Then you say across a domain, whatever that domain can be, aviation, space or thermal dynamics or structures, how do you see across that domain and integrate that content? Both in our forums, in our papers, our publications, it's a flywheel. It all keeps flowing back. So you come here, you present a paper, that goes into our library, we license that library out, and more content keeps coming in and the cycle keeps spinning off more and more high-end content.

So how do we think about organizing around those cutting-edge things? We have a domain leads right now within the organization. We've got task force that we put in place. We also have board-directed committees that try to look across the domain. It's tricky as you can imagine, because anybody who is a practitioner in this business that's doing it, who's the person that's zooming out and looking across the field to understand how does that apply? AI is a great example, but supercomputing we talked about in a lot of these other areas, autonomy. These are areas that cross-cut: advanced manufacturing, additive manufacturing, other areas where they cut across the entire domain. Software guidance, navigation control. These are things that are cross-cutting issues that we have to think about.

So what do we do? We create task forces around these. We try to make sure that... I was at the Publications Committee Group this morning, we were talking about this for about half an hour. How do we make sure that we are thinking about this stuff as cross-cutting, that we can get across that one domain into all of our publications that come out of this? Not an easy thing to tackle, but super valuable, right? Because otherwise you're just focused down and you're looking at your shoes and what's right in front of you. You're not really looking at the bigger, broader picture of how do you implement some of these technology changes to advance whatever your domain is.

Graham Warwick:

I remember being on a panel at AIAA Aviation with you and somebody asked about getting, some young person asked about getting into engineering and how would they recommend it? And I said, "You want to be... The best job is to be an engine expert at an airframe company or an airframe expert at an engine company." I said, "Because the really interesting stuff comes at the interfaces between the disciplines. It's not necessarily within the discipline where you're going to get the real challenges. It's where two things come together. If you want a really interesting career, go for that interface."

Clay Mowry:

When I was a young man, I remember the first conversation I had with someone, it was actually at ESA headquarters, and I was over there and I was talking to one of the guys and he said, "You realize that in our domain it's complex systems of systems engineering and that this is really what is at the heart. It's not just propulsion, guidance, navigation, control, structures, whatever. It's actually figuring out how do you make all these disparate areas of expertise fit and function, something that's flying at super high speed under huge loads, both thermal, acoustic, all the environmental stuff that's going on at the same time and make sure it works perfectly and you put the thing exactly where it needs to go into space." And it struck me from my background. I was like, "Wow, this is exactly..." And so this is what we're trying to do here, and I think you hit the nail on the head.

We're trying to figure out on that systems of systems, how do you integrate propulsion into an airframe? How do you think about how we can achieve better, more efficient air travel, cheaper, low cost, greener, less noise, less pollution, all those things? It's a complex systems of systems approach to what we're doing and we've made huge advances. And you guys are old enough to remember how loud those planes were landing back in our day, taking off and landing and where we are now. And it's just a huge change in terms of fuel efficiency, noise and operability, right? The MRO has gone way down for a lot of these aircraft.

Guy Norris:

We also talked to Clay about AIAA's efforts to boost diversification, and this is what he said.

Clay Mowry:

Obviously there's more women graduating from college now. Attracting them to get into engineering programs and come and work in our industry is a challenge because the demographics are shifting and have shifted dramatically on that. And so we need to be able to attract the right talent to come and work here. So it's great to walk the floor here and see people from all over the world and to see... I've had a chance to work with and mentor some of the young women engineers that are here, some from internationally as well. So we do some work with international scholarship, we run some competitions, some things to try to get folks to come here and present papers and it's been really, it's heartwarming to see them come, want to come here, learn, figure out how to get a job in the business and succeed. So it's really neat to see. I'm glad to see that we're getting... Opening the aperture.

Guy Norris:

Finally, we discuss Clay's vision for how AIAA can evolve into the future.

Clay Mowry:

We're not just a trade show. All of our stuff is built on a technical platform. We have all these papers that are presented. We have a business-to-business platform on top of all of our events, but the core of it is this really important technical discussion and exchange that's going on where people are learning. So we want to make sure that that's a really big part of all the shows we doing. Aviation, ASCEND, SciTech, DEFENSE. We need to embrace that, not that we haven't embraced it, but we need to actually even promote it even more that we have the highest quality technical content that gives a reason for these engineers and technical domain leads to come to our event. Then we can build a really nice platform on top of that. I know this kind of sounds simple, but really in practice it's hard. Where you have these cross-cutting issues, where you look at the big picture stuff, the real big trends, and they evolve every year.

So I don't want to say... Okay, I mean, I can talk a lot about AI and air mobility and green aviation, things like that. And certainly those will be trends in the next year, but I can't even tell you what the trends will be three years from now because hopefully they'll evolve and we'll be on the front end of that. But making sure that we have that content at the top of our events and we give a reason for people to come back year after year. And so my focus and with the staff has been really about that thought leadership, the technical leadership and making sure that... I know it's going to sound a little geeky, but we really want to dig in on that technical front and make sure it's kind of a unique value proposition that we put forward to our events. We're not just like a regular trade show, and I don't mean to run down any of the other shows that are out there, the for-profit industry, but we're doing something a little different as a non-profit, but we want to keep embracing that.

Guy Norris:

Right and that's it. And so Graham, I think we both agreed one of the most bizarre presentations and fascinating was the one that you went to as well. Could you tell us a bit about that?

Graham Warwick:

Yes. Well, I'm just glad I didn't tell Steve Trimble about this because he had already got his underwear in a twist over 5th, 6th generation. There was a presentation on 7th generation fighters and hypersonic aerial gunnery projectiles, and it was extraordinary. A very impassioned, a very, very dynamic presentation by a researcher. And basically his point was that in the US, aerial gunnery ammunition innovation has just stopped. There has been none. There have been no new projectiles, actual bullets, cannon shells developed for aerial gunnery really since the 50s. And they've fallen far behind the Navy and the Army in advancing the ballistic coefficients and everything like that of the gunnery. And to the point where they have just stopped all research. They have two contracts that they compete in essence, to develop this ammunition. There's no incentive to innovate at all and a really, really impassioned presentation.

But meanwhile, there's a consortium of a group of universities that have been continuing to develop hypersonic projectiles. And what they've done is they've developed a discarding sabot, if that's how you say it, sabo, say-bo. Discarding sabot round for aerial gunnery. So basically this has a tungsten flechette, looks like a knitting needle. A tungsten flechette and around it is a sabot that fits it into the barrel. When it fires out of the barrel, the flechette goes forward, and the sabot basically is designed, it's discarded, but it's designed to do a 180 degree turn away from the aircraft and get away from the airplane without... And they know where it's going to go. It's predictable. The pilot can turn and know that they're not going to run into the sabot as it's going. And they've tested these, they've done 10 millimeter, 20 millimeter, 30 millimeter test rounds fired on the ground. Their performance is extraordinary. This thing comes out of the barrel at Mach 5 or something like that.

They estimate that they're in a sort of hard launch from an airplane, it'll go 100 miles with one of these flechettes. So he envisioned having a 7th generation fighter being able to hit targets 100 miles away with this thing. It can be used for counter drone. Thatt's with a smaller round. It could be used on a 7th generation fighter for counter missile at shorter range. The really interesting thing there is, and he tried to explain this, is as the round goes towards the missile, the missile sees it as the target and the missile homes onto the projectile. And actually they annihilate each other. He said it's like an attractor. They can't stop hitting each other because basically the missile, the infrared missile, sees it as the target. And even more extraordinary, at longer range on a 7th generation fighter, you'd fire three of these. They would form a synthetic aperture radar in the sky and guide themselves onto the target at ranges of tens of miles.

Guy Norris:

So they're able to guide themselves even though they're incredibly small, really relative to a missile.

Graham Warwick:

Yeah. So they either have a ballistically aero-stable or a maneuvering aero-stable sabot, but then the round can be either just ballistic or it can have some sort of a guidance to it. He was not able to get into a lot of the details of this because clearly it's fairly sensitive some of this stuff. If they can get the military interested... And then he talked about it's air-to-ground performance. They're able to get the same armor penetration with a 20 millimeter round that the A-10 gets with a current 30 millimeter round. So you can have a much smaller, less recoil gun that could punch through to the upper armor of a tank.

So there's all of these things. So basically he was just making an appeal. There needs to be pressure put on. And okay, his initial target is the AC-130 gunship, and he talked about what this would do. It would basically allow an AC-130 to sit outside of a MANPADS surface-to-air missile threat zone and suppress the entire threat zone of that missile. So we'd be able to just sit there, just outside the threat zone and suppress all the ground within that area, which you can't do in an AC-130 at the moment.

You can use it with suppressors, which means that it swallows the flame, and so you don't see the aircraft when it's firing. It can be used for all different type of things. So he says in order for this to move out of the R&D, they have to get the military to write a requirement for it. So he's trying to get an upswell of grassroots support, to get Special Operations Command to write a requirement for hypersonic discarding sabot ammunition for the AC-130 that will get it into a program system in the DOD.

It's 7th generation because he said it's too late for 6th generation. There's just too many institutional barriers within the DOD to doing anything for 6th generation. We're not even there yet, right? So it just shows you how much the military isn't interested in ammunition, but he said it could completely redefine how you do, not just air-to-air gunnery, but air-to-ground. And it was just done with great panache. It was a great... I apologize for not remembering his name. If anybody wants to email me, I will be able to point you towards him, but my cold prevented me from researching his name, and I apologize for that.

[NOTE – The presenter was Roland Barrett-Gonzalez at the University of Kansas. The paper is at: AC-130 to 7th Gen. Combat Aircraft Design: The Role of Hypersonic Aerial Gunnery | AIAA SciTech Forum ]

Guy Norris:

I love the fact that a potential 7th generation combat aircraft technology could be paved or pioneered on an aircraft that's going to be 70 years old. Fantastic. Well, that's another irony, and yet another example of how broad and varied the material is from the SciTech conference.

Graham Warwick:

Right, Guy. There is always something at this conference that really, really stands out as being unusual. Two years ago or something like that, it was nuclear propulsion. We just heard about it being talked about. One mention. This year, there it is in the presentations. So it's very worth being at this event.

So anyway, that's a wrap for today's Check 6. Thanks to our editor in London, Guy Ferneyhough. And don't forget to follow us in your podcast app of choice. And one last request, if you are listening to us in Apple Podcasts and want to support this podcast, please leave us a star rating or write a review. And bye for now. And thanks for listening.

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