The mystery of the green aircraft

(The original text is the French version of this article.)

Is there still something going on in the aviation industry?

How long has it been since a truly new commercial aircraft was launched?

The world’s design offices have certainly not been idle in recent years. Between the A321 XLR, the B737 MAX and the B777-X, they have had plenty of certification programs. But when was the last time they put a real blank page on their drawing board? The 321 XLR is just a stretched, re-engined, supercharged version of the venerable 320. The 737 MAX is just another 737, certified under the “grandfather rights” umbrella, and that was the reason of its problems. No doubt the B777-X’s expanded cabin and folding wings have kept us on our toes long enough to find something new in this program. Perhaps even its cost has contributed to this perception, but its product sheet and profile picture are enough to set things right. And by the way, it’s a young first-timer with already graying hair that will enter service when it can, as its public presentation dates back to the 2013 Dubai Air Show.

At Airbus, one have to look back up to December 2006 and the 350 XWB program to find the emotions of the “Première” evening parties. At Comac, the C919 was announced in 2010. Launched in 2017, the Embraer E2 was only an upgrade of the fantastic E-Jet. On the Russian side, the Irkut MC21 dates back to 2009.

The older folks remember with nostalgia the excitement of the first decade of the new millennium, when the catalogs of all aircraft manufacturers were completely overhauled. What has happened since? What kind of Sleeping Beauty spell has felt on the aircraft manufacturing world? This business is used to long terms cycles, and has already experienced breaks, but the 14-year wait between the launch of the Boeing 777 in 1990 and the 7E7 in 2004 has since been beaten. The 777-X or 747-8 will not delude anybody. And the long interruption that preceded the birth of the 787 was widely analyzed as one of the main reasons for its pain. So isn’t it time to regroup?

Unfortunately, nothing seems to be able to wake up the aerospace industry in 2023. And there are some very good reasons for this.

Indeed, competitive positions are frozen as they can be in a profession where the division is established. As if, right or wrong, everyone had learned to live within the borders drawn by weapons, and engraved by time. It is a balance that it will take a revolution to break. A revolution all the more natural to expect as it is already in sight. It is called the green aircraft. The next truly new aircraft must be green. It will be a gamble on a scale comparable to the launch of the B707 in 1955, the first commercial jet in history, or the first giant twin-engine aircraft, the Airbus A300 in 1969.

Everyone has his vision of what the green aircraft will be. Visions that are, to say the least, various, in the form of predictions that are more or less self-fulfilling, and therefore more like lobbying than divination. In spite of the very affirmative tones adopted by the influencers of all sides, the very variety of their speeches seems to indicate that the cause has not been heard. “The jury is still out,” they say. And the jury has the right to prolong its deliberations on a bet of this magnitude. Aircraft construction is a business of long cycles.

 

NZ50, or the inevitable SAF FUEL…

Greening commercial aviation is a necessity. Whether you look at it from the standpoint of ecological issues, societal acceptability, the cost and availability of fossil fuels, or the demands of governments, the question no longer arises. And this, all the less so as this activity can afford the transformation. What does this mean? That the customer will put his hand in his pocket, for a service whose value remains real and solvent. The price of the ticket will undoubtedly increase. It is possible that it will cease to be accessible to all, but will all passengers in the world give up this asset? Will the airline industry give up satisfying the solvent market of its wealthiest customers, perhaps reduced in volume, but not necessarily in dollars? No, this is a scenario that will not happen. More likely, companies will adapt to a change in their demand. This adaptation already has a name. It’s called NZ50, an acronym for Net Zero 2050.

The objective is stated. Commercial air transport will be carbon neutral by 2050. And it is telling that as soon as this announcement was made, the societal pressure on this mode of transport, whether it is called flygskam or plane bashing, seemed to have dropped two notches. In other words, the objective is generally accepted by the stakeholders. Why? Because everyone understands how ambitious it is. It is always tempting to ask for more from a partner, but what if they can’t? Demand its demise? But no one dies without a fight. The other option, to hope to do better together than as enemies, leads to trusting each other around the motto of NZ50.

What is it all about, in figures? Transforming a fleet of 25,000 aircraft, whose total gross value, after rebates, exceeds a thousand billion dollars. Such a figure makes you dizzy. So, we must start by taking the measure of it. What can be done with such a sum, comparable to the annual budget of the French State? For example, 5 million homes and houses. We build a city with that much money. So it is a metropolis that we have to replace. In history, we have seen capital cities take off in a quarter of a century. Thinking of Haussmann’s work, what confidence would we have in builders who would claim to go much faster?

And a fleet of planes is not a city like any other. To redesign it, we will not have to rely on all the craftsmen in the world, but on a pair of airplane builders whose capabilities we know well. What can we expect from them, by 2050? A few more years to evaluate the best aircraft configurations, followed by a decade of development and certification, and entry into commercial service around 2035. After that, production will have to be ramped up to S-shaped production rates, timidly at first, then at full capacity. They will probably be able to produce 15,000 entirely new aircraft in 15 years. This will be a considerable effort, which in the past has only been equalled in wartime, and yet will only revolutionize half of the world fleet by the middle of this century. If we can only expect our industry to do half of the decarbonization work at full speed, where will the other half come from? There is only one solution, and it is called SAF, for Sustainable Air Fuel.

What is this miracle solution? A classic kerosene, therefore perfectly compatible with all existing appliances. A kerosene, that is to say a carbon product, but whose synthesis does not draw its carbon from the ground, but from the atmosphere itself. The carbon that its combustion will reject in the atmosphere will thus have been extracted beforehand. In short, the atmosphere will have been cleaned before being contaminated with the same quantities of waste. This is how, by a clever accounting trick, this carbon can be qualified as neutral. On paper, it is as if it did not exist. Of course, it will be necessary to create a production industry for this fluid that is acceptable in the eyes of the regulations, if not of nature. Its cost will not be lower than that of fossil kerosene, but if the future of world aviation is at stake, there will be no hesitation.

So here is a rough outline of what the decarbonized fleet of the middle of this century will look like. One half will be conventional aircraft, powered by a fuel whose greenness will have been negotiated on a carpet of the same color, and the other half will be revolutionary machines.

… and a “freeze-frame” style revolution

Paradoxically, the first effect of the decarbonized revolution will be to freeze the world fleet in a conservatism of more than a decade.

The SAF is an illusion that must be maintained as long as there is nothing to replace it, but we must not deceive ourselves. If we really believe that this carbon does not belong in our atmosphere, then it will not be acceptable to spit it out after extracting it. If it is really necessary to wash the atmosphere of our little planet, it will not be to pollute it immediately with the matter of its former stains. Conventional neutrality will not be a permanent excuse. SAF will have its hour of glory, because in the short term there is nothing else, but this moment will not last forever.

The SAF will therefore only be tacitly acceptable for the duration of its mission, to ensure the link between the models in the current catalogs and their truly green successors. This derogation, tolerated because it is necessary, has a major consequence: neither Airbus nor Boeing have the right to add to their catalogs any new product that would fail to present all the guarantees of authentic greenness. This is how Boeing’s abandonment of its New Midsize Aircraft (NMA) program should be understood.

On both sides of the Atlantic, the Product Road Map calls for a green aircraft, but no one knows exactly which one. Several options have been suggested, but none has stood out. While it has become clear that no conventional aircraft can be launched, accepted, let alone amortized over a sufficient period of time, this does not imply that there is any certainty as to the replacement formula. So let’s get used to a fairly lifeless landscape, to which aircraft manufacturers will only be able to breathe some semblance of life through incremental modifications of their current models. They will continue to fly them, as long as they do not know what to replace them with, and will thus prolong the SAF interlude, as long as the mystery of the green aircraft is not clarified.

This is how our industry has entered an ice age, the beginning of which will take years to thaw, and a quarter of a century to free.

 

What we know for sure…

In a quarter of a century, many things can happen. And guessing what the sky will look like at that time is a challenge. It is clear that on such a scale, a few more years of reflection will not change much in the history of our atmosphere, and can make the difference between failure and success. So such a wait will not be avoided. However, not everything is blurred in the setting of the upcoming play. A number of facts are already clearly visible. What are these certainties, on which to build a beginning of reflection? What are we sure of?

• Nothing will happen in the large aircraft segment. There are several reasons for this:
  • Economic: The aircraft in this segment are the most recent in the aircraft manufacturers’ catalogs, and very far from being amortized.
  • Ecological: Due to their predominant use in long-haul aircraft, and the intrinsic efficiency of this type of use where take-offs are less frequent, these aircraft are already twice as efficient in terms of carbon emissions as medium-haul aircraft (180g/pax*Nm compared to 325). They are therefore not the priority candidates for replacement.
  • Technical: In the world of air transport, innovations come in small modules. In this case, it will not only be a question of renovating the technologies, but also their certification rules. It would be unimaginable to embark on such an adventure on board a Large Carrier.
• As a consequence, and for the same reasons, the first green aircraft will be a small module. The first priority will be to replace the B737, and then the A320, once the competitor has wiped the slate clean. This effort by both aircraft manufacturers and their regulatory authorities will keep them busy for a decade. We must therefore consider an NZ50 scenario based on unchanged wide-body aircraft, powered by SAF, and truly green short-haul aircraft. This is an acceptable scenario, and since there is really no alternative, commercial air transport will have the choice of adopting it or abandoning NZ50. The latter is not the easiest option to sell to the market.
• Among all the possible technologies for this small green aircraft, only one will prevail. Airlines, most of which operate mixed fleets, will not host two different ones to solve the same problem. For an operator, each innovation means new resources, new training and new risks, allocated to very few flights at entry into service. Why would he double the load he can carry only once? Whatever the merits of a second technology to come to market, it would be unable to break through this barrier. Thus, the first manufacturer to announce its choice will be the one to break the tie between technologies. Let them just get their aircraft right, and the next one will have to fall in line.

 

… and the resulting consequences

So much for the certainties. Before getting into technological speculations, let’s look at the consequences of an NZ50 scenario based on a long-haul traffic based on existing SAF-fueled aircraft, and a short-haul traffic based on new and truly green aircraft.

1. A new and truly green aircraft will not only be smaller than traditional medium-haul aircraft. It will also have less range. Whether it is powered by a battery, whose mass energy still struggles to meet the objectives of acceptable performance, or by a hydrogen tank which, even at a pressure of 700 bars, is at best 4 times larger than its conventional equivalent, it will not be able to display a range of several thousand Nm.
2. The successor to the B737 (let’s call it the B797 for the sake of language) will not be an aircraft with identical performance. It should probably be expected in the 100 pax * 1000 Nm range, not far from the regional aviation domain. And perhaps we should not look any further for the causes of the unexpected, and still unexplained, abandonment of the alliance with Embraer. The Reconquista aircraft could hardly be assembled in San Jose dos Campos.
3. The replacement of the traditional single-aisle aircraft with shorter modules in size and range will therefore profoundly transform the continental transport network.
4. Continental transport is used to ensure local mobility as well as to supply long-haul flights. All the passengers in the world will therefore pay their tribute to a totally carbon-free local aviation. Not only in ticket price, but also and above all in the multiplication of flights. The passenger who today goes from Limoges (France) to Buffalo (Wisconsin) in 3 flights and 2 changes in Paris and NYC could well have to consider trips of 4 or even 5 branches. We should not imagine that aviation will be revolutionized in every way, except for the experience offered to the passenger. He too will have to contribute, and he may well accept it, in exchange for an improvement in the way he passes through the airports. Indeed, much comfort can be gained in this segment of travel where mediocrity is still the norm. It is not a question of spectacular bets, nor of pharaonic expenses. It is simply a matter of exploiting all the potential for fluidity of transit offered by digital technology, and for proximity of service, offered by an already dense network of 460 airports in France, and 15,000 in the United States. Of course, not all of the airfields referenced by worldstat are destined to become international hubs in the future, but their land reserves exist. It is already available, and that is the main thing. All that is needed to exploit it is to take an interest in the low-hanging fruit of this part of the journey that takes place on the ground, with the support of regions that are only too happy to be so easily connected to a global system.
5. Smaller aircraft to do the same work from shorter basic distances means much more traffic, flight crews, and ground controls. Such an expansion, coupled with an increased workload due to the sophistication of better optimized flight trajectories, will raise in new terms the question of the size of the technical crew. Will we have to go back to a three-man crew, or will we have to take advantage of digital technologies and redefine the sharing of tasks between man and machine, to finally aim for a single pilot? To ask the question is to have the answer.
6. A densification of the local service network means a multiplication of service stations specialized in the new technologies, whatever they are, that this green device will implement. If we are talking about hydrogen, it will be necessary to distribute it in several thousands of points of the planet, as soon as the device is put into service. If we talk about batteries, they will have to be recharged in several thousand points.

 

… and what remains to be guessed

Which technology? Which delay? Which manufacturer will be the first to pull the trigger? These are the three questions, closely related, that remain unanswered.

These choices can still be postponed for a few years. The time it takes for the dust to settle on the technological battlefield. The challenge is huge. Probably the biggest since the launch of the B707. And even more so, since this time it is no longer a question of creating a new global industry, but of transforming it from top to bottom, without degrading the levels of performance and safety to which it has become accustomed. We are talking about a complete reform of technologies and business models, with the requirement of perfect control of the architecture of the aircraft, its operating data, its lead times, its safety, and its market. It is understandable that tomorrow is a better day than today to take a gamble.

However, time does not weigh the same for all players in the game.

On paper, Boeing has every reason to be in a hurry. After the failure of the 737 MAX entry into service, the Seattle-based aircraft manufacturer was in distress in all segments of its market. Medium-haul aircraft were grounded, production of the 787 was chaotic, the 777-X was not certified, and profitability was down. It was one of those situations that you get out of by launching a new product, but this time with two serious obstacles in your way: a major technological innovation, and the loss of confidence of the authorities responsible for certifying it. How to launch a revolutionary aircraft, in concert with its certification doctrine, in the climate of mistrust that had developed between the aircraft manufacturer and the FAA? The culprit and his unwilling accomplice had no other option than to wait for a return to normal, the first step being the resumption of flights of the aircraft whose name alone had become an insult to their ears. From now on, we’ll have to keep a very close eye on orders for the 737 MAX. If, against all predictions, this aircraft manages to regain its place on the same podium as the A320, the noose will finally be loosened, and Boeing will be able to wait. If not, the U.S. aircraft manufacturer will be forced to move, and will do so with the technologies it has available today.

But where were we at the end of 2022? The gross order counter totaled 561 B737 MAXs after a first year of sales recovery, compared with 888 A320s. This is still a bad figure, but it is difficult to interpret, as it is influenced downwards by the tail end of the crisis, and upwards by a catching-up effect. The figure for 2023 will therefore be decisive. A second year at two-thirds of Airbus’s score would be a clear signal.

Behind this question, whose answer will not be long in coming, lies another, less easy to evacuate: the eternal dilemma between rewarding the first entrant and waiting for the technology to mature. As we have seen above, in the chapter on the obvious, the first to shoot will win the technology match in favor of his favorite. This is a considerable advantage, but its appeal will be balanced by an adverse effect of comparable magnitude: commercial aeronautics has a long history of follower bonuses. The competitor who leads the race offers his opponent a full-scale test bed of all the latest ideas. He takes the wind, leaving the other to sort out the good from the bad. In this, their race resembles those duels of cyclists, where each seeks to suck the wheel of the other as long as possible, to overtake him at the last moment. Those who are used to racing on the track enjoy the spectacle of these immobile racers, remaining frozen as long as they can after the start signal. The best carbon plane is not the 787, but the 350, launched two years later. And this lesson is multiplied on the eve of an adventure a hundred times more revolutionary.

During this round of observation, where everything is about patience, balance, nerve control, and misinformation of the opponent, let’s not doubt that the promises of the two major energy storage technologies will be re-evaluated right up to the last moment: hydrogen or battery.

 

On the hydrogen side

Hydrogen has been presented in Europe as the latest good idea. And it is true that this solution has some merits. The technology is perfectly mature. For decades, space launchers have mastered the storage of this fluid in large quantities. The fuel cells in charge of converting it into electrical energy were developed for the Apollo program. It is even possible to run thermal engines using hydrogen as fuel. Moreover, there is already a production line for industrial applications of this element.

However, the advantages of this solution also measure its limitations.

First of all, there is little progress to be expected from proven technologies. The theoretical storage volume of the lightest fluid in Mendeleev’s periodic table is four times that of kerosene, and will remain so until the end of time. And the real volume will be much higher for a long time, because to store at 700 bars, there are only cylindrical forms that hold. Under such pressures, it is out of the question to slip a few more liters into a last forgotten nook or cranny, in the wings or fuselage of the aircraft. This lack of density will have lasting consequences on its aerodynamic performance, the exploitation of its interior volumes, and ultimately, its autonomy.

Secondly, we must ask ourselves what to expect from the existing hydrogen production chain. To what extent is it adapted to the needs of commercial aviation?

• In terms of global capacity, it produces 60 million tons every year, which, in terms of energy equivalence, would barely cover the needs of the single-aisle segment.
• In terms of ecological quality, its production method, by cracking 96% of methane, could hardly earn it a green award.
• In terms of logistical deployment, its distribution network is built around a few relatively concentrated industrial consumers. This is the opposite of a network of several thousand airports, as scattered as possible over the planet.

It is therefore a new infrastructure, which will have to be created for the needs of green mobility. Creating a new infrastructure is not a problem in itself. We understand that aviation will not decarbonize without a minimum of efforts. But in order to finance these efforts, we must at least be able to say what economic performance is targeted. The cost of using any new infrastructure depends essentially on the volume of its production. And apart from aviation or traditional industry, in quantities that we have seen are marginal for the latter, what are the other potential users of green hydrogen? The automobile, and that’s it. With a global fleet of 1.5 billion vehicles, the automobile is not the other major consumer. It is THE big consumer. Commercial ships are giants, but in numbers too small for their overall needs to matter. Modern trains do not carry their energy. Besides these anecdotal prospects, the needs of the automobile are potentially ten times greater than those of commercial aviation. So, from the point of view of the operational costs of a hydrogen aircraft, it will not matter at all whether the automobile industry makes a global commitment to this technology or not.

That is to say, it will be impossible to know the real economic performance of a hydrogen aircraft as long as the automobile issue has not been resolved. In other words, to be able to sell, and above all buy, a hydrogen aircraft today, its economic performance must be considered viable, even without the support of the automobile sector, since this is not yet guaranteed. Therefore, the single-aisle segment alone would have to justify the development of a global, autonomous and extremely dispersed supply infrastructure. Until this economic equation is resolved, the aerospace industry will have to wait for the automotive industry to make up its mind. At this stage, the least we can say is that it is far from it. Let’s remember, to convince ourselves, the terms of the equation. The cost of producing green hydrogen in small quantities is currently around $4.5/lbs, whereas the economic model to be aimed at is based on figures comparable to those for methane cracking, around $0.5/lbs. In other words, the economic performance of a hydrogen aircraft depends essentially on decisions that will be taken at an unknown date, outside the aeronautical industry and its control. It is difficult to launch a program on such a shifting basis.

We must also note that the inventory of climate damage created by commercial aviation is not limited to the single line of carbon emissions. The CO2 effects are the easiest to understand, and that is why attention naturally turns to them, but it is not certain that they are the most important. The ISAE-SUPAERO (French aerospace engineer high school) climate benchmark, whose quality must be highlighted, estimates the non-CO2 effects of aviation to be twice as high as its CO2 effects, with a weight of 86% for contrail-induced cirrus clouds. It should be remembered that water vapor is also a greenhouse gas, just like CO2. This consideration should not be a pretext for inaction, but an invitation to study, because it is also specified that the non-CO2 effects are much more uncertain than the CO2 effects. It is therefore necessary to understand them better, before putting everything into the development of a machine to replace carbon by these long white trails in the sky, which we might realize on the way that they are worse than the evil.

So, from the point of view of both the economic environment and global climate issues, the decision to launch a commercial hydrogen aircraft seems difficult in the short term. It’s not that this solution is definitely bad. It is not even that it presents too many technical difficulties. But it requires clarifications that will not be available in the short term. It is this uncertainty that makes it incompatible with a rapid launch of the green aircraft, for example by a cornered Boeing. Paradoxically, it is the urgency to act that would first condemn the hydrogen option.

Other storage solutions

The ideal solution would be to store all the energy needed for a flight in a good battery. All that would be needed would be spare batteries and/or recharging capacity at every airport in the world, and that would be it.

Unfortunately, the mass of batteries capable of ensuring this mission would exceed today’s good old kerosene tanks by a factor of 60. Which is a lot. Battery performance is evolving, but not at the rate of Moore’s Law. Chemistry is not electronics. One plays with ions, and the other with electrons, which are considerably lighter. However, there is still a factor to be gained in this field, and it would be all the more foolish to deprive oneself of it, as the developments will be financed by other industrial sectors.

In fact, there are several areas where important factors can be gained:

• Battery capacity. As we have seen, not everything will come from this field, but it is undoubtedly possible to aim for a factor of 2 in the long term. Maybe even a little better.
• By not trying to cover the 6000km of an A320, but a distance 3 times less, we gain a factor 3 without great risk or effort.
• The architecture of the aircraft. The classical architecture (ie: A cylinder overhanging two wings overhanging two engines) is out of breath. It is necessary to be aware of the deformities which accumulated on this model, entirely drawn around engines whose diameters did not cease increasing in their race with the ratio of mixture. Driving the fans not by a mechanical shaft, but by an electrical power supply, would allow to redefine the number, the distribution on the aircraft, the rotation speed, and even the redundancy scheme. The geometry of the aircraft would be freed, as well as its mass and aerodynamic performance. This would lead to the design of revolutionary shapes? Yes, but it is the revolutionaries who make the revolutions, and they do not shy away from the objective of gaining another factor 2.
• Where would the rest of the gain come from? From several sources, as usual. The efficiency of electric transport is still very mediocre on a conventional aircraft. It could be doubled by the development of geometries or, why not, by the use of superconductors. The trajectories in the sky can also be smoothed. Are we going to continue to trace our route with the ruler-rapporteur of Admiral Jean Cras, model 1917, as in the time when energy was not a subject? Don’t we have, in the 21st century, calculation capacities that allow us to do a little better?

The battery-powered airplane is therefore not a completely crazy option, but it still suffers from a major handicap: it relies on the battery of tomorrow, whereas we need it today. Even if they do not follow Moore’s law, improvements are nevertheless possible in the field of storage. So tomorrow’s battery-powered aircraft will always be better than today’s. And this will be an excellent reason to ground it permanently.

And that’s where the word hybrid comes into the conversation.

An airplane is not a hybrid like a car. Its hybridization has a different purpose. It’s an aircraft designed around all-electric thrusters, which are themselves powered by two sources, either battery-based or traditional thermal power units (powered by SAF, as it should be). Hybridization is therefore here a simple duplication of electricity sources. Why this luxury, on board a machine whose mass is being reduced at all costs? Because, on the one hand, the two have different characteristics, which are needed according to the flight regimes. The takeoff is a violent and brief thrust. Level flight is a smooth, long thrust. This first idea allows us to optimize the architecture of the aircraft; but to make it completely green, we need the second, which is to change its batteries as their mass performance evolves. Thus, at the beginning of its life, the same aircraft could rely more on the electrical energy produced by its thermal machines, and at the end of its life, on its latest batteries. Such hybridization would allow to rely only on part of the advantages of the new architecture at the beginning of its life, and to improve its ecological performance progressively, with the improvement of the storage processes. The beauty of this design is that the ecological transition can be achieved on board the same aircraft, under the same Type Certificate. This makes it possible to amortize over 30 years a machine whose performance is always in line with the best technological standards for batteries.

The hybrid aircraft, and this is its greatest merit, is certainly very new in terms of its design, but it relies solely on technologies available today. It can therefore be launched today.

 

Who has an interest in what?

It is interesting to meditate on the devices of tomorrow, but one must not forget that in order for us to see them one day, it will be necessary that those on whom we count to build them have an interest. Hence the question, which is necessarily too briefly addressed here: who has an interest in what?

– Boeing has the highest interest in getting out of its predicament, and can hope to do so by launching a new, necessarily green, aircraft. If the 737 MAX doesn’t get back on track soon, Boeing would better not wait too long, either with a last classic-futuristic avatar of the TTBW (Transonic Truss-Braced Wing) type, or with a true green aircraft, which can only be a hybrid.

– Airbus has a vested interest in making the most of its current strong position, based on a better catalog in all market segments. This may not last. We’ll see what the 777-X is worth at. But for now, Airbus’ interest is to let Boeing get stuck and shoot first, to observe its inevitable mistakes, and learn from them. In doing so, Airbus will have to give up the privilege of imposing its technology, but as we have seen, this privilege is filled with pitfalls.

– Engine manufacturers have an interest in favoring the solution that will least disrupt the “razor and blade” business model of their engines. It should be noted that engine manufacturers are now the masters of the equipment chain, which aircraft manufacturers need to design their next aircraft. The green aircraft will not be built without them, and even less against them. From this point of view, the hybrid aircraft is probably a more realistic solution, because it is safer for them, provided they retain control of the entire propulsion and electrical generation system. This should not be out of their reach.

– Aircraft manufacturers would obviously have the opposite interest, to regain, through a technological revolution, some authority over the engines of their aircraft, but it is doubtful that they would still be able to make such a claim.

– Airlines have an interest in a smooth and economically sustainable transition, including for the smaller ones, limiting the bets on possible decisions by other industrial sectors. They will also want a single technology to be proposed to them for the decarbonization of their fleets. From this point of view, it should be easier for them to adopt a hybrid vehicle.

 

Let’s not forget Comac

At the end of this quick overview, which aircraft seems to meet all these challenges?

A 100-pax, 1000Nm, single-pilot hybrid aircraft, launched by Boeing in a small number of years – less than five years. The only real calendar constraint to launch fuch an aircraft is the need for the FAA to regaine enough confidence and authority to certify it.

Such an aircraft forces us to look beyond the traditional boundaries of our industry. Because here it is: this aircraft is also Comac’s favorite candidate.

• Comac knows how to develop and certify a device of this size, thanks to the experience acquired with the ARJ21 and the C919.
• Comac has a sufficient domestic market to take the risk of such a development.
• Comac also has the complicity of its Regulator.
• Comac can access all hybridization, electrical storage and battery technologies developed for the Chinese automotive industry.
• Finally, Comac has the desire and public support to become the real 3rd world aircraft manufacturer.

 

Olivier Zarrouati, Thélème

April 11^th, 2023