Podcast: Inside NASA’s Sustainable Flight Plan

As NASA invites bids to build and fly its Sustainable Flight Demonstrator, technology editor Graham Warwick and senior editor Guy Norris hear how this aircraft will differ from the agency’s prior X-planes. They talked to Rich Wahls, NASA’s newly appointed Sustainable Flight National Partnership mission integration manager at the AIAA Aviation 2022 conference in Chicago.

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Rush Transcript

Graham Warwick:

Hello, and welcome to Aviation Week's Check 6 podcast. I'm Graham Warwick, technology editor, and with me is Guy Norris, our senior editor. We are at the American Institute of Aeronautics and Astronautics Aviation 2022 conference in Chicago. And Guy, this is the first time I've been able to join you at one of these conferences for quite a while, so give me an idea of what you think about this conference. What are the themes or the observations so far?

Guy Norris:

Yeah. Well, as you say, it's the first time. It's almost like standing back up to normal again, isn't it? A return finally to that. I know we have had a few early false starts, like SciTech, of course, in January. You wouldn't say there's a false start, but I feel like this is the first time when we've actually got a good crowd. Everybody's on message. It's not a sort of tentative thing, which I think AIAA was pioneering, really, in January. But this time I feel like it's back to more like normal. So what we are really seeing at the moment is a lot of debate about the workforce issues facing the aerospace industry, as a whole. There's been a lot of talk about the supply chain pressures, of course, that's facing all aspects of the industry. And I think that was really underlined in the first few sessions here as well. It's not just commercial, it's the defense.

Graham Warwick:

Yeah. So Rod McLean from Lockheed Martin used an interesting phrase, which I've never heard before, because he said it's not about just in time anymore and having just the one thing on the wall that you need. It's about just in case, and having as many of them as you can get to, in case the supply chain is disrupted.

Guy Norris:

Yeah, that's right. The just in case. I'd never heard it described like that, but I'm sure he wasn't the only one who was thinking that. And of course, as usual, the great thing about AIAA is that you get to hear things that you'd never hear at other conferences, all under one roof. So we've talked about things like trajectory-based operations and what's going on with hypersonics. So it's just been, as usual, a great sort of wellspring for us. Keeps us going for a few months, I think.

Graham Warwick:

Yes, it does. Yeah. So we actually have a special guest with us on this podcast. So the huge theme here, and it's deliberate, but it's also, you just can't avoid it in aviation these days, the big theme is sustainability. So yesterday, NASA did it’s now kind of annual presentation of its priorities and programs to the conference, and the Associate Administrator for Aeronautics, Bob Pearce, announced that the solicitation for the Subsonic Flight Demonstrator, which is a big X-plane program, literally went out yesterday. The clock is now ticking towards this. And he also announced that a very good friend of Aviation Week, and a very good friend of Guy and I, Rich Wahls from NASA, who's with us today, has been named the mission integration manager for the Sustainable Flight National Partnership (SFNP).

 

Rich you'll have to explain quite how that fits but, to me, it's kind of the umbrella for both not only the Sustainable Flight Demonstrator, but a whole bunch of other technology demonstrations that are supporting this idea of having the technology ready for a next generation, single-aisle-class aircraft by the mid 2030s. So, Rich, Bob created news yesterday, and he gave me some work that I had to do last night when I got back to my room. So, welcome, and could you give us a rough idea of what it is, what you want in the form of a Sustainable Flight Demonstrator, and what you want it to do?

Rich Wahls:

Yeah, so the Sustainable Flight Demonstrator (SFD) is going to be focused on advanced airframe configuration technology, enabling a step change beyond the conventional configuration we have today. And although it will be the biggest project under the SFNP, the Sustainable Flight National Partnership, it's not the only project. There's the SFD, but we also have technology demonstrators for gas turbine engines, for hybridized gas turbine engines, that we call HyTECH, and the Electrified Powertrain Flight Demonstrations that you've written about and talked about, where we already have contracts awarded there. That's part of it. And HiCaM, that's the high-rate composite aircraft manufacturing project, that's part of it.

 

And we have some other activities that are a little bit lower level that feed into and that. The Transonic Truss-Braced Wing (TTBW) is a technology development project that we've been working that we expect will be one of many proposals that comes in for the SFD. So we're having a competition for a reason. So those are kind of the technology elements of the SFNP, and then we also have some near-term sustainable operations demonstrations that we book under that, and some supporting work for fuels that we contribute.

Graham Warwick:

Yeah. Yeah. So what is it you want this thing to do?

Rich Wahls:

Yeah, so it provides an opportunity for that configuration change that we've all thought was coming at some point, but never gets there. And part of it is that it's such a big change. There's so much risk involved for a company to make a change like that, that we never get across the valley of death. A lot of alternative concepts kind of hit show-stoppers along the way, but there's several that haven't hit those yet. And the next logical step is a large-scale flight demonstrator, the size of a single-aisle transport, plus or minus. So we haven't received the proposals. We don't know exactly what it'll be, but we're envisioning single-aisle transport class-size demonstrator aircraft that's of an alternative configuration.

Rich Wahls:

We expect that it'll have, what I would term, broadly applicable technologies that enable that concept, but would also be applicable to a conventional cantilever-wing concept. The current schedule has it flying in fiscal 2027. But in the near term, the request for proposals yesterday was a huge milestone that came right down to the wire. We were trying to get it so we could announce it here. The proposals are due September 1st, as I understand. Somewhere, I don't know exactly how long it'll take to award, but I would view that as kind of December, January, somewhere early in probably 2023.

Graham Warwick:

So one unusual aspect of this is you're actually going with this Funded Space Act Agreement. So there's about $425 million in the NASA budget, which would go to the partnership through the Space Act Agreement. Then you'd spend some more money internally on supporting work, and then the industry would put matching funds or something like that against that.

Rich Wahls:

Yeah. So this and all the SFNP projects are at least cost matched by industry. Commercial aviation is core to these companies' businesses. They're motivated. So we're sure there's going to be kind of at least a 50/50 cost match. And then if they want to add additional technologies and use this testbed, it could go beyond that on their part. The Funded Space Act Agreement, of which I'm not an expert in, and there's people on the team who are, but the Funded Space Act Agreement, as I understand it, there'll be milestone payments as it goes along. It's more we'll have insight into what's happening. We'll work together. They'll have access to the NASA civil servants and facilities. That's part of the budget that is beyond that number you mentioned. And so we don't really know what the proposals will be that'll come in and what the final cumulative dollar figure will be, but you can tell by the size of that number, it's a big project. It's the biggest one I've ever seen in my life.

Guy Norris:

You and Bob Pearce have both likened this really to sort of a [Boeing] Dash 80 type moment as well, potentially.

Rich Wahls:

That's what I think, because, I mean, we've seen subscale flying demonstrators. The [Boeing] ecoDemonstrator is a great program, and it adds technologies to current airplanes, but not the architecture-changing airplanes.

Guy Norris:

Oh, and we should remind listeners that the Dash 80, of course, was Boeing's famous sort of transport/tanker combined demonstrator that spawned not only the KC-135 and the legacy of those transports, but also the 707, and was the originator of Boeing's modern 7-series commercial jet line.

Graham Warwick:

And it really brought in a new configuration, didn't it, with the swept wing and the underwing podded engines.

Guy Norris:

So it was a game changer, of course.

Graham Warwick:

And that's kind of how you see that the potentially here is this could-

Rich Wahls:

It's a step change and architecture-changing kind of thing. And so whatever demonstrator we do, I hope we get across the valley of death. I hope that the industry partners, there'll be a prime for sure, and a team, kind of a national team, if you will, it's kind of like a Team USA, that's all going to be learning. And then when the time comes to make decisions on what the next product airplane is, I hope that they have all the information. I expect they will have all the information they have to make a good decision. And if it doesn't happen, I think all the supporting technologies are going to benefit, no matter what it is. But if we don't do this, there'll never be a change.

Guy Norris:

One thing that Graham mentioned yesterday was that he'd said that you weren't going to officially apply as NASA for an X-plane designation, but it would be up to whoever wins the competition. Is that right?

Rich Wahls:

So we may be part of requesting it, but you have to request it in the military.

Graham Warwick:

Yeah. And Bob said it’s because they won't own it. It's one of the things about this Space Act Agreement that the industry's really in charge. I mean, they set the pace, they set the priorities. So it's really the idea, I think, behind it is to give the industry really much more control and flexibility to-

Rich Wahls:

To build off all the research that we've been doing together and all that. But compare and contrast with the X-59, the supersonic demonstrator, that's one where we put out a request for proposals, we got bids back, and an airplane is going to be delivered to NASA. NASA's going to fly it, and NASA-sponsored researchers will be gathering the data, synthesizing the data, providing the analysis. So it's being delivered for a NASA purpose. In this case, we're not going to get delivery of the airplane. We're not going to own the airplane. It'll still hopefully become a national asset that, down the road, could be re-utilized, but it will be not our property.

Graham Warwick:

And as Bob was laying it out, I thought an interesting aspect of this is really, it's aimed to get as close to commercialization as you can, while within the [WTO] rules and everything like that. But the combination of getting the technologies across a broad front as mature as possible, to TRL 6 [technology readiness level] by the end of this program, ready to go into product development. But I thought the interesting part of it is of course the high-rate composites, because as he said yesterday, whatever comes out of it, whatever product comes out of this, it's got to go into the fleet quickly in order to make a difference to the climate impact. So you have to design the aircraft and have all the technologies ready to go very quickly to that 70, 80 a month rate that's taken years to get these other programs to get to. We've got to get to those quickly, because we've got to get these into the fleet.

Rich Wahls:

Right. I think if using truss braced or blended wing body, as an example, you could fly and it could get the L/D [lift-to-drag ratio] and feed that into a fuel burn benefit. But if you can only produce them at five a month, then the economics don't work, and you don't transition. But it's really key - we're not developing a product. We're not funding industry to develop a product. We're trying to get across that TRL valley of death and, in the broadest sense, to a total technology readiness, the integration we really have to understand with this demonstrator, the trades. And the flight test will be extremely important, and there's other things you can do on the ground in parallel.

To learn some things about icing, there's things we can do on the ground first. And then eventually, you go fly in icing, but the demonstrator, that's not the tall pole for the demonstrator. It things like aeroelastics, where flight aerodynamics, flight Reynolds number and real aircraft structure, not model structure, come together with the flight control, things like that, that you need to fly, to really understand. The blended wing body and the truss-braced wing are very different in that one's got thick airfoils and one's got really thin airfoils. There's different challenges for each of those and they have different manufacturing challenges or opportunities as well.

Guy Norris:

So the next time probably all three of us will be together, we should know the outcome and who's going to be-

Graham Warwick:

At SciTech.

Guy Norris:

SciTech, yeah. Yeah.

Rich Wahls:

I think that's towards the end of January next year, so we have a few extra weeks into January, so I would hope so. I would have to go ask our project manager, who's got the real schedule, but it's that kind of timing.

Graham Warwick:

And these AIAA meetings have become quite eventful actually. It’s a bit like if you look at the business aircraft industry, you look at when did that airplane come along? It's always NBAA, right? Everything gets launched to either EBACE or NBAA. And AIAA SciTech and AIAA Aviation have come become sort of like milestones in the research industry, where we try to get things ready for that. And it's appropriate in this bizarre hotel, the Hilton Chicago - there's no straight line from A to B in this strange place. But this is where the Chicago Convention was signed, which is what created the International Civil Aviation Organization. So there's a real deep-seated link to aviation in this hotel, and we may have seen the beginning of a generational change in aviation, here at this hotel.

Guy Norris:

Right. Well, and just as importantly, this was used for the filming of the movie Fugitive with Harrison Ford.

Graham Warwick:

Hopefully we won't be back as fugitives.

Guy Norris:

Yeah, that's right. But we might feel a fugitive at times.

Rich Wahls:

I learned about the Chicago Convention thing this morning. I always knew about the Chicago Convention. I didn't know this hotel. So that's actually fascinating.

Guy Norris:

Yeah. Quite appropriate.

Rich Wahls:

And to your other point, 2016, I think, at AIAA Aviation, was where X-57 Maxwell got announced and named, and then a few years after that, I remember our project manager for X-59 coming out with the name on a banner. It's a good flagship event for NASA aeronautics.

Graham Warwick:

Yeah. Yeah. Well, that's it. So folks, I think we'll call that a wrap for this week's Check 6 podcast. Today, we've been talking about technology, which is what Guy and I usually talk about, that and football, whatever that is. But if you want to learn more about air transport, check out Aviation Week's new Window Seat podcast. Like Check 6, it is weekly, and it is available on all the same podcast platforms. And one last request, if you're listening to us on Apple Podcast and want to support this podcast, please leave us a star rating or a review. Thanks to all of you who have shared your positive feedback so far. It's great to hear you appreciate what we are doing, and have a great week.

Graham Warwick

Graham leads Aviation Week's coverage of technology, focusing on engineering and technology across the aerospace industry, with a special focus on identifying technologies of strategic importance to aviation, aerospace and defense.

Guy Norris

Guy is a Senior Editor for Aviation Week, covering technology and propulsion. He is based in Colorado Springs.