Podcast: Airbus' Next Clean Sheet Narrowbody—What We Know So Far

Jens Flottau Guy Norris Sash Tusa February 02, 2024

As Boeing's 737 program has dominated the headlines, more details are emerging about Airbus' plans for a new clean-sheet narrowbody, but when could it launch and will it generate significant emissions savings? Aviation Week editors are joined by Sash Tusa, an analyst with Agency Partners and regular guest columnist, to discuss.

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Transcript

Jens Flottau:

Hello, and welcome to this episode of Check 6. My name is Jens Flottau, and I'm the executive editor, commercial aviation at the Aviation Week Network. Boeing has been dominating the commercial OEM news since the start of the year, more precisely, since January 5 when an emergency exit door plug blew off a Boeing 737-9 in flight. The accident made an already difficult situation much worse and raises all sorts of questions about the future of Boeing, including its ability and willingness to develop a successor for the 737. Today, we want to focus on Airbus and talk about what Airbus's next narrowbody could look like, and when it might be available. With me today, are Sash Tusa, an aerospace analyst at Agency Partners in London, and also, an Aviation Week columnist in his spare time, and Guy Norris, Senior Technology Editor at Aviation Week, who has been following new aircraft programs at both Airbus and Boeing for decades.

I want to kick this off with a strategy question. In 2023, Airbus received two thirds of all narrowbody orders, obviously for the A220 and the A320neo family. The largest share of that, of course, went to the A321neo. Airbus is sold out until 2030 or so. If anyone could decide that now is harvest season and we are focusing on financial returns for a few years, it's probably Airbus. Airbus could also wait and see what Boeing does to react with something better. Now, I had the chance to talk to Christian Scherer, Airbus's new commercial aircraft CEO, just after he started his new job in early January. He said to me that they aren't going to wait for Boeing to act first, but go ahead with their own aircraft anyway. Sash, do you buy that and why would they do this?

Sash Tusa:

Jens, I think it's possible. I think that it's looking more likely, almost for some of the reasons that you've given that would suggest otherwise. Airbus, historically, has had, or certainly for the last decade or so, has had a view that they could wait to see what Boeing produced, take a couple of years, and then come out with something better. That was one of the very big lessons that Airbus learned from the launch of the 787. With the 787, Airbus rushed into a response with the original, well, it was a warmed up A330, which they called an A350. That, as we remember, was a disaster. They had to write that off, go back and redesign the A350 XWB. It cost them at least five years and probably 5 billion euros in terms of sunk costs and compensation and so forth. The lesson then was wait for Boeing. Here's the problem, Boeing is probably crippled financially. Doesn't want to launch anything themselves, but the clock is ticking in terms of net-zero.

Airbus cannot wait for Boeing to launch, and then two years on launch, and then a 10-year development program and credibly get this industry towards net-zero. I think there's a realization now that there will have to be interim aircraft designs. Airbus is the only OEM that's financially strong enough to launch one. Yes, there is a risk of cannibalization, that part of their backlog, which is eight years plus for the A321. Part of that backlog will switch to the newer aircraft. That's a risk they can afford to take, and this would get them an aircraft with hopefully, significantly, but probably not dramatically lower emissions sometime in the 2030s, I suspect no earlier than 2035. That shows the industry is willing, the industry is prepared to keep moving towards net-zero. Keeping on producing A320 737s I think will attract an increasing amount of political pressure because it would suggest that the industry doesn't care and then they might be forced into something they really don't want.

Jens Flottau:

Guy, we've been hearing a lot from the university that it doesn't make sense to do a new aircraft as long as the technology is ready. A lot of work has been going into the next generation aircraft already. Airbus has got the Wing of Tomorrow research program. GE and Safran are working on the RISE engine. Can you fill us in on where we stand technologically and when we might be ready to merge this all into a new product?

Guy Norris:

Well, you're right, Jens. The thing about the Airbus strategy is it's backed by this large investment, which is we've got some public awareness of as well, because some of it is backed by, in Europe anyway, by some publicly-funded industry government programs to establish this sort of building block approach or technology bricks, as Airbus likes to call them. As you rightly say, it's across airframes, systems, aerodynamics, propulsion. We recently, just in a couple of weeks ago, the AIAA SciTech conference got an update from Sue Partridge, who's the head of the Wings of Tomorrow program. It was important to look at it from two aspects. It's not just about the aerodynamics and the technology for that, but it's also about the production capability, the manufacturing. Can you do this at a high rate from day one? It's like a multi pointed program, which aims to establish the industrial credibility of something as well as the technological.

Obviously, they're joined at the hip somewhat. It's a key part of any assessment when you look at the technology readiness for a next generation single aisle, is can you build them at the rate people expect to have them these days? The same thing applies for the fuselage. They have a program which is similar, really. It's the thermoplastic fuselage section, eight meters long, same cross-section as an A320, totally made of thermoplastic composites. Again, highly automated robotic assembly techniques and things like plastic welding. There's all that going on with the airframe. The thing that was really impressive about the Airbus presentations was the fact that there was a succession of demonstrators to prove that this just wasn't a science experiment.

These are demonstrator-built for demonstrator, each one pushing the state-of-the-art to a new level of capability. As I said, technology readiness and manufacturing readiness, all being brought along at the same time. Then of course, the other areas you mentioned is propulsion. We're seeing a lot of acceleration this year, particularly on the RISE program. A lot of wind tunnel testing. In the US, of course, elements of that going on with GE, of course, doing a lot of testing here at Evendale, and working with NASA really as well on the equivalent side as part of the high-tech program, looking at super small core technology, which would be an engine like a RISE open fan. Anyway, that's a quick thumbnail of where things are with that.

Jens Flottau:

If we look at it today, what is the aircraft going to look like that they're going to design? How conventional will it be? How disruptive will it be on the technology side? Just basic parameters, how large does it have to be? Is it going to be A321, is it A220? What's the range?

Sash Tusa:

I think it starts at the A321 and goes higher. Airbus is over 60% A321s at the moment. I suspect that if they could, they would push that higher. The market clearly wants larger aircraft. One of the ways that European governments, and Europe tends to lead the way in environmental issues like this, one of the ways that European governments are dealing with the challenge of net-zero is by capacity constraints. Just limiting the number of slots. Look at what has happened at Amsterdam's Schiphol Airport. It has been slots that are cut first and that forces aircraft sizes up as they've already done at London's Heathrow. You start at A321, you move up. Airbus is a very elegant solution anyway at the bottom end, which is to stretch the A220 to the A220-500.

It doesn't need a 500 seat, sorry, 150 seat anymore. Start at 180 and you really should be pushing to 240 if you can. As to what it looks like, I think that, that is the single biggest issue relating to engines. If CFM's RISE is selected, it's very, very hard, or at least I think it's going to be a much more challenging engineering process to put those on or under a wing. Noise in particular is going to be a massive problem there, particularly inside the cabin. Plus, the issues of blade off. Just on noise for RISE, I am unfortunately old enough to remember the previous generation of unducted fans flying at various air shows at Paris and Farnborough, and they were shockingly noisy. There may be some secret sauce somewhere or not on RISE, but I don't see it.

If it's a conventional engine, and that would mean something like the GTF Advantage from Pratt and Whitney or Rolls Royce's UltraFan, it can look fairly similar to what we've got at the moment. Just I think one other point that I'd make, which is slightly broader, I think one of the reasons why Airbus is thinking about this now is there is a realization that there cannot be a single leap from today's generation of aircraft to a wonderful hydrogen-powered blended wing, totally futuristic design. There has to be an interim design. Now, that's bad news because it means you have to go through a whole design cycle that you rather would not go through. I just don't think the industry can wait a decade or so, then launch the blended wing H2 program. That way, you can come out before 2050 at this rate.

Guy Norris:

Just to follow up to Sash's comments, he raises some great points. From the configuration perspective, one thing that's really come out apparently with the Airbus Wing of Tomorrow program is they're acknowledging that even for A320-size airplanes, you're talking about much bigger, almost A330-size wingspans, 767-8 size spans for a much smaller aircraft. Of course, technology will evolve, is evolving to cope with that, both in terms of, I think we're going to see, for example, folding wingtips become a common site. The 777X will introduce it on big airplanes, but you're going to see. I think that by the 2030s, that will be a common site at airports.

Jens Flottau:

Guy, sorry to interrupt you. I just visited Liebherr-Aerospace here in Germany, and they're doing work on the 777X folding wing. That's exactly what they hope will happen. They want folding wings on their bodies, be it 737s or A320 successors. Sorry, but go ahead.

Guy Norris:

No, you're fine. Of course, beyond that, you have this idea of a semi-aero elastic hinges, which would be part and parcel of that, where you're not simply moving in that outboard section to reduce the overall span, but you're actively using that as a variable hinge mechanism to enable loads to be taken throughout the span of the wing in flight. That would allow you to optimize that structure in a much more different way than today. Who knows particulars? You go forward to the next generation when you're looking at a dry wing with hydrogen, for example, tankage in the fuselage. It just opens up the aperture to all sorts of new concepts which aren't even possible today. The other thing about Sash's mentioning about configurations with these large diameter engines, whether you're talking about open fan or semi-conventional looking high bypass ratio engines within a cell, Airbus has decided, at least for the purposes of the studies at the moment, that whatever they're going to do will be a standard wing, but a raked high wing.

Whatever they've got, even for RISE, which is looking at about a 13-foot several meter diameter or main rotor diameter, that it would be able to be positioned, even for a narrowbody, under wing. It's not really under wing at all. It's actually a gull wing, if you can imagine. The wing root is currently where it is today, but immediately rises up. I mean, think about a, do you remember the DC-10? It had that a similar gull look. Anyway, that's the way they're beginning to approach this. On the noise aspect, certainly, Safran, they're pretty sure that with the idea to go to a single rotating stage backed by a static guide vane stage, it does away with so many of the harmonic problems that you've got with the counter rotating stages of the UDF era conducted fans that Sash and I remember from our days preparing sounds of egg beater noises as these demonstrators flew at Farnborough, for example. I think we have to yet to hear, witness that in real life. They're not going to go even to that stage if they're not convinced they can't make that leap in noise reduction.

Jens Flottau:

What kind of emissions reduction is really realistic in the timeframe that they're looking at, like 2035, '36, '37? Are we talking 20%? Are we talking 30%? Sash, do you have a view?

Sash Tusa:

Well, there's two separate things. There's fuel burn and there's emissions. Different, and I think that emissions will be very, very driven by the fuel use. This is possibly where SAF comes in, although I continue to be cautious about SAF because I just don't see the capacity going in. With SAF, I don't think that it should be possible even with the engines that we're talking about now, which are known or relatively known technology. GTF Advantage is definitely that. RISE, more radical. Rolls Royce's UltraFan, again. Those should be able to reduce emissions by the order of 25, 30% and possibly, some emissions by more than that.

The issue will be fuel burn. I suspect the fuel burn will be in the teens. Now, as it turned out, airlines killed for that with the current generation of A320neos and 737 MAXs. That was a fantastic issue if the airframe can then go along with that. I think that there will be a mismatch between fuel burn and emissions and it will be very, very fuel dependent. It's clearly nowhere near what would be achieved with hydrogen. I think that, that is now end of the 2030s with a lot of fingers crossed. This, of itself, does not get the industry anywhere near net-zero, but what it does is it shows intent.

Jens Flottau:

If Airbus goes with RISE for this aircraft, will it automatically be single source or is there a way for that, for example, to come up with an unducted fan as well?

Sash Tusa:

I don't think Airbus will go single source on a high-volume narrowbody aircraft until they absolutely have to, and this generation is not it. I think the lessons they've learned with the Pratt and Whitney Geared Turbofan, which is that if your engine manufacturer lets you down, you are in deep trouble and your customers are in deep trouble is a real issue. They also look at what's happened with Boeing, with 737 MAX, but also, with the 777 and the 777X. I think Airbus wants to stay or would like to be able to stay dual source for this program, if at all possible. I think the issue of how you configure an aircraft that can take both a RISE and a more conventional geared fan, that's an enormous engineering issue.

Guy Norris:

Just to follow on from Sash's point there, I think the decision that they're looking at, at least for the studies to go with this gull wing, for example, would enable it to be agnostic as far as propulsion is concerned. You could put a pretty large diameter nacelle-based engine into the same slot as you could mount an open-fan engine. I think to keep their options open, not only from that perspective, but also to provide the baseline so that all of these propulsion systems and even the configuration for the fuel system could ultimately be converted to hydrogen burning should that eventually happen. I think that's another aspect about the technology side of it.

They have to be able to guard that capability to expand so that even a 320 fuselage will be built in A321 dimensions to make sure that you can put tankage in the 2040s say, for an aircraft that could then be the same length as today's 321, but carry today's 320 passenger load with hydrogen tanks. I think the last point that I want to make Jens, is that we're seeing a bit of evidence that hydrogen is being kicked further down the road at the moment. Nothing official yet, but the feeling definitely out there is that we're not going to see an A320-sized hydrogen-powered airliner in 2035. It's probably going to be, there's going to something out there, but it's more likely to be a small turboprop than a mainline single aisle, as far as we see anyway.

Jens Flottau:

Sash, you've always been a hydrogen skeptic, as far as I'm concern. Do you agree with Guy?

Sash Tusa:

My skepticism about hydrogen is fundamentally that the technological challenges are enormous and there is no fuel that is acceptable. If you just put in hydrogen that is produced in current generation chemical plants, which is by its absolute essence, dirty and carbon intensive. You're not achieving what the hydrogen dream is, which is a fuel produced by, probably powered by solar, and which is completely green all the way through from its creation to its use. That technology is not maturing, anything as fast as we would like. I think Airbus would like it. Airbus has been very clear, they see hydrogen being the future. I don't disagree with that. The question is when the future is.

The other big issue now is that SAF, synthetic aviation fuels, which are sometimes rebranded as sustainable aviation fuels. It's an interesting piece of greenwashing. Even SAF capacity is not coming on as fast as expected. Our feeling is increasingly that SAF might become a rather special fuel that is reserved for long haul. Long haul is going to be the hardest sector of this industry to decarbonize. It may be that it has to go SAF, but SAF is reserved for long haul flights, in which case, we're again have to do really well with current generation fuels. Hence, this interim and Airbus airline that we're talking about.

Jens Flottau:

That's all we've got time for today. Special thanks to Sash and Guy for joining and for the really interesting discussion. Also, special thanks to our podcast producer in London, Guy Ferneyhough. Don't miss the next episode by subscribing to Check 6 in your podcast app of choice. One last request. If you're listening to us in Apple Podcasts and want to support this podcast, please leave us a star rating or a review. Bye, for now.