Hydrogen, electric and hybrid alternatives not here yet

By Scott Hamilton

Sept. 25, 2020, © Leeham News: Commercial aviation has had 70 years to use jet fuel safely. It’s unclear how long it will take to reach the same level of safety with hydrogen, say Boeing.

In a briefing Tuesday, the day after Airbus revealed its hydrogen powered concepts for three potential airliners, the vice president and general manager of product development expressed caution about hydrogen as a fuel source.

Unique promise, ensuring maturity

Mike Sinnett said hydrogen has “unique promise just looking at the chain of how it can be created and consumed and the emissions that result. The difficulty is always around the practical implementation and engines and how you ensure that the regulatory environment and the technical environment progressing together and maturing at the same time.

Mike Sinnett

“We have come to enjoy a significant level of safety and it’s improved dramatically over the course of the last 70 years of the jet age,” Sinnett said.

“We know a lot about how kerosene is burned and how it can be stored safely, how it can be transported and how engines use that fuel in all environments from the Arctic to the desert.  We’ve got a wealth of knowledge and experience that makes the air transportation system very, very safe today,” he said.

Sinnett said that as the industry transitions to more sustainable fuels, it’s necessary to ensure that there’s no backpedaling in those levels of safety.

That means that there’s still a lot to learn about how you would create and transport hydrogen and use it in all operational environments, from the Siberian winter to an Algerian summer, he added.

“The safety requirements regulations have to mature at the same time that the technology matures. I believe we see promise in a transition to more hydrogen-based fuels over time. However, I would caution that I don’t believe it’s something that’s right around the corner. There’s a lot of infrastructure and regulatory framework that has to evolve with the technology. That is not a fast process,” he said.

Electric power

For a time, the buzz seemed to be leaning toward electrically power airliners. However, as LNA’s Bjorn Fehrm detailed in a lengthy series on the subject, the limitations of electrical motors for large airliners are huge. Airbus also downplays the use of electric motors on airliners the size of the A320.

Sinnett doesn’t see this technology around the corner for anything larger than small airplanes.

“With the technology that we have [in the] next five years-ish timeframe, the electric technologies are sufficient for smaller airplanes in shorter ranges,” he said. “There’s something intuitive about that when you think about how the technology advanced for automobiles.”

He said automobiles are now getting to the point where the ranges are getting close to the ranges of a gasoline-powered or a diesel-powered automobile.

“You also probably have a sense for how much weight is involved [for] the batteries that are in those automobiles. Automobiles are certainly a lot less weight sensitive than aircraft are,” he said.

With current battery technology, there are applications where shorter ranges with much smaller airplanes are practical today, he said.

“However, when you look at our business and the air transportation business, and you project forward in the near term, applications are going to continue to be for smaller airplanes over shorter ranges because the energy density and the power density in current battery technologies, and even in the battery technologies that are in labs right now, aren’t sufficient to be able to do the mission of today’s single-aisle turbofan powered airplanes,” Sinnett said.

“There probably isn’t a technology on the horizon yet that would allow long haul operations done by today’s twin-aisle airplanes like a 777 or a 787 on alternate technologies. Those are further down the line,” he said.

Hybrid power

Hybrid technology only complicates things. Instead of one technological power source, there are two.

“For hybrid solutions, one of the other things to think about is the complexity of the hybrid architectures can negate some of the benefits. If you have an electric motor and you have a turbo gas turbine, now you’ve got two things on the airplane, where in the past, you might have only had one,” he said.

Two different sets of technologies carry more weight and more complexity.

“We always have to make sure that the benefits and the fuel burn and emissions outweigh the detriments of the increased complexity and weight,” he said.

A future article will detail things Boeing is pursuing in eco-aviation.

108 Comments on “Hydrogen, electric and hybrid alternatives not here yet

  1. Sounds like he has his head screwed on.

    On top of that, if external pressure requires emissions modification before hydrogen is ready, will the air transport industry be happy with the hassle/cost/disruption of hydrogen following on soon after the hassle/cost/disruption of a near term alternative?

    In terms of actual product development, if BCA decides it needs a MAX replacement before hydrogen is possible (my bet), goes with it and is able to move far enough ahead of the A32x to make the A32x uncompetitive, then does Airbus hold back and suffer near term in hopes all the stars align soon after to go with a hydrogen competitor? Or does Airbus respond in kind? I’m guessing that airports would rather not need 2 sets of infrastructure for competing bulk fuels that need storage.

    BTW, there is an interesting recent paper from the Royal Society of Chemistry that looks at lifecycle costs of alternative aviaton fuels at https://pubs.rsc.org/en/content/articlehtml/2020/se/c9se00788a

    • @Woody

      IMJ, any near to medium term MAX replacement can be countered by a cheap Mark II version of the A320neo (i.e. UltraFan powered etc.).

      The problem for Boeing is that the market share for the MAX appears to be shrinking — big time. Post Covid-19 recovery (2025?), Boeing’s single aisle market share could well be lower than 30 percent. Thus, they would have to do something.

      By launching a conventionally-powered MAX replacement in, say, five years, Boeing would be facing a high risk of obsoleteness for their new and shiny aircraft at EIS.

      Despite the crisis in the industry, Airbus is sitting extremely comfortably in the single aisle market — and it appears that they will continue to do so for the next 15 years. Boeing is in a lose-lose situation. They’re already late-to-market (big time) with Airbus now eating Boeing’s lunch with the A321neo/A321XLR.

      The MAX is currently Boeing’s achilles heel. That’s why Mike Sinnett appears to be talking down the new ZEROe initiative from Airbus. If an Airbus ZEROe single aisle aircraft family comes to fruition as an A519/A520/A521 family in 2035, Boeing has essentially lost the battle for the single aisle market for, at least, the next 15 years. So, the ZEROe initiative from Airbus is not only about a “zero” emission replacement aircraft for the A32Xneo family, but it should also be viewed as a factor in the competitive business for Large Commercial Airliners (LCA); namely through game-theoretical modeling, where decisions by one player dependent on the moves expected of the other player. In game-theory terms, the response from Airbus vis-à-vis a near-term Boeing MAX replacement aircraft (797X) must be viewed as a threat, changing Boeing’s potential rate of return for developing the 797X. In short, if Boeing goes ahead with the 797X, Airbus is obviouskly planning to undercut it using an aircraft based on the existing A32Xneo design.

      Likewise, if Boeing would expect Airbus to launch an all new revolutionary “zero” emission single aisle aircraft in the early to mid 2030s, surely they would be getting ever more hesitant towards launching an all new but conventional 797X replacing the 737MAX in, say, 2030. In short, if Boeing would go ahead with a conventional 797X, Airbus would be threatening of undercutting the 797X with not only an all new revolutionary design, but one that would also more than comply with the 2035 emission standards.

      What’s obvious, though, is that the airline industry cannot continue to ignore the elephant in the room: carbon emissions. Up until now the public and the airlines have not demanded significant change from the OEMs. One way or another, carbon regulations are coming big time to the global airline industry. Never mind that climate change denial in the U.S. is the original “fake news”, the imminent change in global greenhouse gas emissions regulations is poised to leave the U.S. behind in a world embracing action on climate change. Due to repeated policy failures in the U.S. (i.e. “voluntary standards” etc.), the U.S. aerospace industry will be under no pressure from the current US Government to improve the fuel efficiency of aircraft — a competitive disadvantage in today’s world.

      • I would say its less the MAX Achilles heel, and its Airbus Single aisle product line. No question of the enormous financial impact the MAX debacle has had.

        But with the A220 in the Sub 737-8 category, as well as its ability to take over the 737-8 with a stretch (and the GTF is going to have a major upgrade occur making it worse for the 737-8)

        Airbus can continue the A320 for what operated want or need that and The A321 is going to eat more and more Boeing lunch. Same GTF improvements and CFM has to match it (at great expense) or be road kill.

        While the 787 is stellar (once they figure out how to make a quality product) – Airbus can offer the A330NEO and cap it with the A350 that is far more flexible than the 777X.

        In short Boeing has one good product and Airbus has 4 (5 if you put the A321 in a separate category which is treading deeply on the separate Boeing 757 area)

      • “We have come to enjoy a significant level of safety and it’s improved dramatically over the course of the last 70 years of the jet age,” Sinnett said.”

        Pretty sad how Boeing only applies that to fuel.

  2. Agreed that hydrogen represents a sea-change for manufacturers, airlines, and airports alike. It will be some time before there is any hope of widespread commercial adoption. That will require equally large changes in energy infrastructure.

    In the meantime, the EU effort should help to define the problems and potential solutions, so will serve as a learning exercise. If it results in a commercial product, that will be welcomed as well.

    • I would expect EU defined solutions to be through the lens of EU (well, almost entirely French and, soomewhat less, German) weaknesses and strengths and aimed for maximum competitive advantage.

      I think there is genuine and very real possibility of a nascent hydrogen economy by the 1930s in the EU/EFTA/UK/CH but the only obvious point to focus on to me is domestic energy provision (I really don’t see cars going hydrogen until battery car development and factory costs have been repaid at the earliest) and already countries are diverging. For example, the NL and UK both have large numbers of domestic gas boilers, the pipelines that go with them (which in the UK at least will all have been renewed and suitable for hydrogen by the mid 30s) and high population density. But NL has chosen to disconnect properties in order to phase out natural gas whereas the UK is muttering about switching boilers from natural gas to hydrogen instead, and countries with larger house plots heat pumps may be preferred etc.. So could end up hydrogen having insufficient mass.

      • Using a mixture of up to 25% H2 and NG, in the existing pipelines, might help introduce hydrogen. It requires not much investment and has an immediate return of about 15% reduction in overall carbon emissions.

        Also for those entities that might want pure H2 (such as airports), they can extract the H2 and reinject the unused NG back into the pipeline.

        Until there is enough renewable generation capacity to support electrolysis, methane reformation can be done alongside NG production at refineries. But the reformation would need to use carbon capture to see a net carbon emissions benefit.

        So this would be a low-cost way to get started with H2, with options to expand and shift further toward zero-carbon with additional investment. It also allows for learning and fallback without disrupting the economy.

        • The old style coal gas system for cities produced a product that was around 50% H2 and was piped around easily. The major problems came from having around 10% carbon monoxide.

          • Claes, in studies the aging was not seen to make a significant difference. The largest contribution is permeability over long distances.

            Pure H2 in NG pipelines has a leak rate about 5 or 6 times that of NG. In a blend of 20% hydrogen, the leak rate of the mixture is about double NG alone. However the observed rate is about .0oo5% of the quantity flowing in the pipeline. It’s about 2.5 liters per km per day. The leak rate is monitored in pipelines to keep the rate low.

  3. The US is an oil producer with huge oil/gas interests globally, France and Germany are puny oil producers but both produce electricy and have large gas companies. The US has no deep urge to tax avaition fuel that it is in the EU. Aircrafts with huge LH2 tanks and systems are not as simple, light and efficient as JET-A burning Aircrafts that emit CO2. So Boeing will wait as mainly US widebodies operate into EU and those will use JET-A1 or bio verions of it for the forseable future. Only the 737MAX will get problems in the EU if they switch all narrowbody operations to LH2 operations, but everybody except Ryanair, Norwegian, Icelandair and Sun Express and some charter companies buy the A320series. Ryanair and Norwegian will be missed by few of its competitors…

    • It’s likely though, that the 737 will still remain cheaper to operate. So unless there are regulatory or tax incentives to compensate for the cost differential, it will still have a market in the EU.

      Which may mean that Airbus will retain fossil fuel versions. And outside the EU, the infrastructure for hydrogen won’t exist, so Airbus would still need those versions for those markets.

      • We will see, with Iceland, Norway, UK and Turkey outside the EU there will be few EU registred 737MAX’es making it easier to ban them from landing inside the EU if they do not accpet LH2 fuel.
        I agree that Airbus must produce the A320neo for other counteris and might do a major block change introducing a new carbon wing, new Engines and Al-Li fuselage but that is like going from 777-300ER to the 777-9 on a smaller scale, not a brand new Aircraft with all new systems like these.
        The UK with its oil/gas business will probably try to stop LH2 fuelling services in the UK, but they have massive investment sin wind Power so they would probably export LH2 to the EU.

        • @claes

          Norway and Iceland are both part of the EEA.

          Norway is a member of the European Aviation Safety Agency (EASA). Norway is part of the European Common market in the field of aviation through the European Economic Area – the EEA Agreement between Norway, Liechtenstein, Iceland and the EU Member States. Within the EEA area all countries have common safety regulations issued by the European Parliament and Council as well as the European Commission.


          • Yes, but EU makes the rules, if you are not a member you have limited possibilities to influence the decisions. Note that many other industries are working towards H2 power as well but not as visible. Both the EU and the US see problems of making some oil producing countries (that are non democratic) rich and see no problems in cutting todays money flow to the Middle East, Nigera, Russia, Libya, Venezuela…

        • The 737 couldn’t be banned for that reason unless fossil-fuel Airbus versions were also banned. Also the hydrogen powered versions may not have the range to cross the Atlantic, so fossil fuel NB versions will still be needed, including the 737.

          • Reality is a Hydro plane is an all new bird.

            EU can do anything they want in regards to sunset of fossil fuel Single Aisle.

            Reality says that they then the new Hdryo Bird is limited to the EU and that is not a viable model.

            The whole world is going to have to change for Hydrogen to be viable and I don’t see that for 40 years if then.

            The big question is where is the best bang for the Green Buck, ban coal plants first, you can regulate Jet-A to cleaner (and quit burning off the Rain Forrest )

        • Nearly all countires, except the US, stand behind the Paris Clima Agreement. It’s practically impossible to reach the goal, of limiting the global temperature increase to 2°C, without huge implications in the commercial aviation.

          No company will start an airplane development program, if it’s not clear, that it will comply with the world wide regulation scheme in 2035. There is just no business case for any fossil fuel powered airplane program anymore.
          What the plane makers need now, is a roadmap from the worldwide regulators. If a deadline for fossil fuel powered airplanes will be set, this would mean a huge aircraft replacement market. This would be the business case for an aircraft program with extraordinary high development costs.

          • The Paris accords set overall goals but did not mention aviation. So it’s possible (and necessary) to pursue those goals outside of aviation. Especially since the contribution from aviation is well under 5%.

            The argument has been that all sectors must participate to reach the goals. But aviation could still participate by other means than conversion to hydrogen.

            As far as Woody’s point below about dual product lines, I think the first commercial hydrogen aircraft will be regional and a niche product. Thus adoption will be mainly in the EU and will depend on rollout of hydrogen infrastructure for airports.

            Then if that is successful, and many airports have the infrastructure in place, there can be development of the NB hydrogen market, but it will still be mainly in the EU.

            So I think the idea of mass replacement of the larger fossil fuel aircraft is not realistic. It will be a gradual change and other countries will follow the EU example if it’s viewed as successful.

          • I have to agree with Robs overall assessment.

            Only disagreement is regional. I don’t see a very minimal market regional working in the EU.

            Might was well mandate trains.

            Airbus wants to put no money into the successful ATR let alone an all new bird. I can see their point with small sales.

          • The EU can ban JET-A aircraft below say 100t MTOW flying in the EU when there are alternatives, just like when they banned Stage 2 noice aircraft and the hushkitted ones just within stg 3 limits. They might start with turboprops to get experience and not piss off the US too much initially before moving to narrowbodies and finally widebodies. I think both parties in the US get huge funding from the Oil/Gas companies, so no matter thee rsult of the president electio in Nov they will not embrace LH2 aircrafts even though they might get goverment funding to convert the PWA and GE engines to buring LH2. Just look at the AVGAS piston engine fuel getting phased out when JET-A1 diesel piston engines getting available. Most of them desiged with different Mercedes diesel engines as the baseline for the aeroderivatives.

        • I think the opposite is probably true of the UK. UK oil/gas is way past peak while hydrogen for domestic energy has been getting a push for a few years already and, publicly at least, the UK is keen to “lead” on hydrogen.

          Norway, UK and Iceland are also big on wind/hydro/thermal, with a need for smoothing storage and hydrogen as a possibility.

          Turkey? Cosy Russian oil/gas?

          As for parallel “avgas”/H2 product lines, how is anyone (except a Chinese state backed player perhaps) going to afford this?

      • @Rob

        A 737-800 may well be slightly cheaper to operate than an A320ceo. Believing that the 737-8 MAX, post grounding, would be cheaper to operate than the A320neo seems somewhat misconstrued.

        • Reference was to fossil-fuel vs hydrogen-powered aircraft. The MAX and NEO have similar operating costs. The NG and CEO costs were both higher, but again similar.

          • @Rob

            Fair enough, but conventionally powered aircraft are likely to face significantly more stringent emissions regulations in 2030 — a world in which carbon taxes for the aviation industry increases at the rate of, say, 5 -10 percent per year.

            When a ZEROe-type civilian airliner enters into service, regulators are likely to have significantly increased taxation on carbon based fuels. Thus, the fossil-fuel vs hydrogen-powered aircraft comparison is likely to look very different 10 years hence than what the case is today.

            Carbon taxes are charges on the carbon content of fossil fuels. Their principal rationale is that they are generally an effective tool for meeting domestic emission mitigation commitments. Because these taxes increase the prices of fossil fuels, electricity, and general consumer products and lower prices for fuel producers, they promote switching to lower-carbon fuels in power generation, conserving on energy use, and shifting to cleaner vehicles, among other things. A tax of, say, $35 a ton on CO2 emissions in 2030 would typically increase prices for coal, electricity, and gasoline by about 100, 25, and 10 percent, respectively. Carbon taxes also provide a clear incentive for redirecting energy investment toward low-carbon technologies like renewable power plants.


          • I believe I allowed for that case:

            “So unless there are regulatory or tax incentives to compensate for the cost differential …”

          • @Rob

            No, the reference was:

            So unless there are regulatory or tax incentives to compensate for the cost differential, it will still have a market in the EU.

            You write as if this is still up in the air. The fact of the matter is that taxation of carbon emissions are set to grow significantly in the EU, over the next decade. Hence, it’s not about if, but rather by “how much”.

            While the U.S. has been dithering on the issue since the Rio de Janeiro Earth Summit in 1992 — thanks, of course to the GOP; an organisation which, BTW, Noam Chomsky has claimed to be the most dangerous organisation in world history * — the EU and very likely China, will lead the world in regulating greenhouse gas emissions.

            * https://www.ecowatch.com/chomsky-goodman-climate-change-2426716028.html

            Which may mean that Airbus will retain fossil fuel versions. And outside the EU, the infrastructure for hydrogen won’t exist, so Airbus would still need those versions for those markets.

            It’s quite amusing how you seem to believe that outside the EU, there won’t exist any hydrogen infrastructure post 2030. What seems to be the case, though, is that the rest of the world can now clearly see that the U.S. Government — assisted, of course, by the corporate carbon lobby — has not only been actively working against doing anything about the issue, but that it has been actively sabotaging environmental controls domestically as well as internationally, for quite some time.

          • The basic point was that even if the EU is successful in developing hydrogen infrastructure to support aviation, it will be some time before it is deployed to the rest of the world.

            Since Airbus relies on a global market, they will still need fossil fuel offerings. That makes it unlikely that the EU would close airspace to fossil fuel aircraft.

            It could be that those aircraft will also move toward biofuels or synfuels, in parallel with the hydrogen development. The EU would be unlikely to close airspace in that scenario either.

            I think the problem occurs when people try to force the outcome they personally see as best. At present we have an initiative with many uncertainties, and none of us know exactly where it will lead.

          • @Rob

            You write down your points seemingly oblivious to the fact that all major developed countries — that is, apart from the U.S. (California excluded 😉 ) — seem to be betting heavily (or are starting to bet) on a hydrogen-fueled future.

            While the U.S. as a whole barely merits a mention in terms of green hydrogen development, one state, California, is racing to become a world-leading market.

            California’s interest in hydrogen is driven partly by aggressive decarbonization targets, including phasing out all diesel or natural-gas-powered buses by 2040, and partly by the presence of some of the industry’s most high-profile technology developers.

            Foremost among these is Silicon Valley-based fuel-cell maker Bloom Energy. But the company is still struggling to achieve something no publicly traded fuel-cell company has ever done: turn an annual profit.

            10 Countries Moving Toward a Green Hydrogen Economy

            Japan was the first country to adopt a “Basic Hydrogen Strategy” and plans to become a “hydrogen society”. The nationwide hydrogen market is expected to grow 56-fold to JPY 408.5 billion (approx. CHF 3,7 billion) by 2030, providing exciting business opportunities.


            Quote: Since Airbus relies on a global market, they will still need fossil fuel offerings. That makes it unlikely that the EU would close airspace to fossil fuel aircraft.

            Nice try, but I was talking about what may transpire after, say, 2040 when the industry would have started to churn out ZEROe-type at a significant rate — and due to public pressure at that point in time, the EU along with Japan, China, Australia (etc) could be pushed by the public, policymakers (etc) to outright ban all aircraft using carbon-based fuels just as zero emission aircraft would be available in numbers.

            Meanwhile, Airbus appears to be set to be owning the single aisle market for, at least, the next decade — which is a nice situation to be in when you’re preparing to launch a new revolutionary product.

            Quote: It could be that those aircraft will also move toward biofuels or synfuels, in parallel with the hydrogen development. The EU would be unlikely to close airspace in that scenario either.

            That appears to be a non sequitur.

            Again, many of the same developed countries (mentioned above) are also supporting R&D targeted at the recycling of atmospheric CO2 into synthetic fuels, using renewable energy, which offers an energy concept with no net CO2 emissions.

            Quote: I think the problem occurs when people try to force the outcome they personally see as best. At present we have an initiative with many uncertainties, and none of us know exactly where it will lead.

            What is certain is that as the rest of the World plans a green recovery, the United States is once again falling behind.

          • I can’t make my position any clearer. Your vision is that the world will quickly move to a hydrogen economy and the US will be left behind and locked out. That outcome seems very unlikely.

            The hydrogen economy faces numerous obstacles, even in the best case. So I don’t think it will be straightforward, there will continue to be competition between resources and all will advance in parallel. Probably resulting in some evolving balance.

            If we build renewable energy resources in the 3 to 1 ratio needed to support hydrogen, then direct use of those resources will also compete with hydrogen. That is inevitable. Also closing the carbon cycle with carbon-based fuels becomes more tenable with cheap and abundant energy, so that too will compete.

            I don’t know where the balance will fall out, but I do know there is likely to be a balance of some kind. It’s not likely that there will be only one solution.

          • I can’t make my point any clearer. Your vision is that the world will move to a hydrogen economy and the US will be left behind and locked out. I think that’s not very likely.

            The hydrogen economy faces many hurdles, even in the best case. If we build renewable energy resources at the 3 to 1 rate that is needed for hydrogen, the direct use of that energy will compete with hydrogen. That’s inevitable. Abundant energy will also make closing the carbon cycle for carbon-based fuels more tenable. So it’s likely that options will develop in parallel with hydrogen, based on advancements and competition within those options.

            I don’t know what the ultimate balance will be, but I think it likely there will continue to be a balance of some kind. That will happen in the US, as well as elsewhere in the world.

          • @Rob

            What appears to be the case is that clean hydrogen is currently enjoying unprecedented political and business momentum, with the number of policies and projects around the world expanding rapidly. Now is the time to scale up technologies and bring down costs to allow hydrogen to become widely used.

          • We will see. As has been pointed out by many here, the cost will be quite large and the challenges many. To do the research and explore the options is perfectly fine, but to declare victory or certainty in the outcome, is very premature. I’d rather let the research determine the outcome.

        • OV-O99:

          I am in now way anti H2, its worth research and pilot projects workign with it. But its a major issue for storage and distribution, either very high pressure or very cold temps.

          Current political aspects in the US are a short term impact (hopefully).

          H2 may be cleaner, but it has a cachet of cost adder, from what I can tell at least 30% .

          I carbon tax is a matter of a small amount, then you just pay the tax.

          If is mandated 30%, then the market shifts – EU can become a backwater.

          The issues with wind and solar continue to be storage. Fossil fuel (hopefully natural gas) is easy to store and bring on line and take off line as cycles occur.

          Yes you can do huge battery banks, along with huge cost, there is a huge carbon footprint for batteries. Lead Acid is recycled, but Li Ion is not. Batteries are not free lunch.

          They wear out, they fail. So you have a large maint aspect and have to build redundant parallel lines so you can take a whole line out of service to replace a single bad battery (break the chain link and its done). You hope for a non event separation, a violent one can occur.

          Natural gas is easy to move and uses relatively low pressure and the flow into a home or business is very low pressure ( 3 psi in the US if I recall right).

          Jet-A you just dump in a tank, H2 you have to keep really cold, which means refrigeration and that is a major cost all by itself.

          To me it looks like at least a 50% penalty overall. 90 people in an A320 class. So you double to foot print to move the same number of people.

          • “”To me it looks like at least a 50% penalty overall. 90 people in an A320 class. So you double to foot print to move the same number of people.””

            There is no reason LH2 tanks should be so heavy.

          • As Bjorn points out, the tanks can be much lighter, but they have to be cold.

            Ergo you need refrigeration units. The tanks don’t fit into a wing (limits on the insulation needed to keep cold) so they go in the fuselage, taking room.

            All in all its likely doable, but range is limited and the weight, longer fuselage, which is more weight, refrigeration, more weight and power to run refrigeration you don’t have to now all add up to much higher combined costs.

          • You can buy LH2 around the world just like Coca Cola, the key is the huge volumes required for commerical airlines, but as demand increases the global gas companies making money selling it will figure out how to increase production and availability around the worlds airports to make more money for its stock holders.

          • LH2 is also perishable due to its cryogenic temperatures and loss rate. NASA pays under $4/kg for LH2, but buys twice what they need to account for losses. This is not carbonless LH2, so those costs would be higher.

            The NASA number is delivered, so liquefaction and transport is included. The production cost is probably 60% of that.

            If produced from methane reformation, the rule of thumb is 3 times the cost of natural gas, on a unit energy basis. Each kg of LH2 produces 10 kg of CO2 from that process. So to avoid the carbon problem with capture, you need to add about $0.50/kg LH2. at commercial scale.

            If produced from electrolysis, the rule of thumb is 4 times the cost of electricity, on a unit energy basis. This is carbonless so no carbon capture needed.

            However the electricity is not carbonless unless the source is renewable or nuclear. We don’t have enough of those resources at present, so they have to be constructed. The numbers above do not account for those costs.

            We could also use carbon capture with fossil fuel generation. Each kg electrolyzed LH2 produces 60 kg CO2 through generation. The capture cost would be about $3/kg LH2.

            So moving to hydrogen would be expensive and require a large investment. It’s sensitive to he cost of other sources of energy, and will compete with them. Therefore I think it will find selected uses among a balance of solutions. Aviation could ultimately be one of those, with significant changes in design and tolerance for higher cost. But other technologies will likely remain in play as well.

      • I can see a transition period where both systems operate. I’d be willing to pay the premium to fly on a zero emissions jet. I can also see companies putting in place travel policies mandating zero emission flights above others.

  4. I’d like to see a comparison of hydrogen economics vs synthetic jetfuel (i.e. jetfuel synthesized from organic sources or even direct from CO2).

    Jet fuel per se is not the issue. Its origin from fossil sources is the problem. Were it derived from atmospheric sources of CO2, it would no longer contribute to the climate change problem.

    The ratio of energy to weight for jetfuel is pretty hard to beat, is my understanding. And we understand how to safely handle it, the infrastructure is already there to do so, and we have 10s of thousands of aircraft that already use this fuel source. Transition to jet fuel that’s not derived from fossil sources and you don’t have to change anything else.

    • The link Woody posted above gives a good overview of life-cycle costs and emissions levels for the various alternative jet fuel options. Worth a read to understand the issues with each. As you said, any deviation from fossil fuels has an associated cost increase. So a matter of deciding which would be best.

    • The advantage of CO2 capture to make JET-A1 is that it also consumes huge amount of electricity with similar economic effect on goverment coffers as LH2 production does. Still it is a drop in replacement requiring no new aircrafts and will be much harder to regulate the actual mix-in ratios into regular JET-A1, the opportunity for cheating is endless, EU cannot even regulate and enforce virgin olive oil as 75% of tested EU suppliers are cheating.

      • And we can mention the Diesel Emissions Variance (not VW Cheating) where they left holes so large in the protocol as to be worthless.

        US is good at putting teeth into its regs and yes they still cheat from time to time, but they have to work hard at it and get caught.;

  5. In some ways, an analogy can be made to the end of steam locomotion in railways — which didn’t follow a straight path, went at different paces in different countries, and resulted in different alternatives.
    – Electric locomotion is regarded as the most efficient and clean, but it requires additional infrastructure (electrification), which is expensive both in terms of one-off investment and maintenance. This is, perhaps, somewhat analogous to the LH2 situation in aircraft.
    – The other big alternative in rail is diesel, which is king for very long and thin routes, and where electrification isn’t practical (such as dockside usage, in combination with overhead cranes). This is, perhaps, somewhat analogous to the alternative hydrocarbon fuel situation in aircraft.
    – There are hydrogen-powered trains running in some countries (e.g. Germany). These are mainly being tried out as an alternative to diesel on lines where the low traffic doesn’t merit electrification.
    – There are also some pilot projects with battery-powered regional trains…again as an alternative to diesel on quiet lines.

    Analogous to the checkered situation with rail, one could, for example, envisage a situation whereby smaller regional planes might be the first to convert to LH2, followed by (a subset of) A320/737-sized planes, with widebodies burning synthetic hydocarbons for a long time to come. Lightweight private aviation might convert to battery power (and, indeed, is already doing so).

    • Bryce:

      I see the points but a Locomotive is a low cost program vs an aircraft of the 737/320 type.

      So the economics can be fuzzed around the edges. Even the diesels are diesel electric so the electric part is not a whole new tech for a railroad.

      We are experimenting with natural (this is from 2017)


      And its really an overall emissions figure(s) we are looking at.

      If we want to have the economy that feeds and gives a decent living standard (no we are not there) to the worlds population – then the question is, what part does Aviation play and make that possible.

      Clean up what you can and Aviation does what it can but continues down the fossil fuel road as an outlier may be the answer.

      At best a Single Aisle is around a 10 billion cost (if you don’t muck it up). That is a once in 30-40 year investment.

      Boats float, car and vehicle of all types (including locomotives) run on wheels.

      Plane have to fly as well as roll around (vastly less rolling and vastly more flying as it were)

      Its a unique category.

      And its truly a world wide issue. Chinese emissions don’t stay in China (nor US and I forget but we are 1 and 2 in some order)

      That said the US started on a cleanup in the 70s. Long road and the first emissions regs were a setback as they caused more pollution by the major drop in economy.

      No one is talking about the Carbon footprint of building a Jet.

      And in irony, there was a big movement not to send our garbage to China.

      Ironically, that is where it comes from now, so they should take it back!

      The US has had a hugely successful lead acid battery recycling program for 30 years (or close) now. Simply put, if you want to sell batteries in the US, you are responsible for the whole mfg to recycle. The battery breakdown goes to regional centers and each battery mfg pays its part of that cost (and gets their lead back) . In the last 30 years I think I have picked up one battery left by the side of the road.

      EPA approach on diesels was to hit the biggest polluters first (over the road trucks) as they had both the quantity and the miles run.

      They then applied the tech to the next group until all were regulated and now almost all are Tier 4 (5?). Some exceptions for standby power Generators that run less than 100 hours a year (mine were about 55, mostly testing)

      What is needed is a uniform world wide (or as much as you can get) approach to where the best bang for the emissions buck is.

      That may be helping another part of the world out getting rid of big polluters to the benefit of all (and yes there are efforts there that have been sabotaged by the US, hoping to change that soon!)

      • If you go by emissions, transfer from coal to natural gas is a huge impact on CO2 emissions. Enforcing replacement of home oil/natural gas heaters to ground heat pump heating and air conditioning is next. Using wood instead of concrete for construction where it is possible also gives an impact. Similar with cars by swapping out gasoline, diesel for GNG and battery power. All these takes political guts and skill not easily found in most countries so aircrafts is an easier target with a feeling that the business travelers will pay any price to fly and other powerful industries can copy thier solutions for their business.

    • Except that standards back then were national, manufacturers were national and many, product lifecycles short, volumes large and costs (comparatively) miniscule.

      I don’t see how developing a new line as H2 rather than avgas could avoid being substantially more expensive, yet without global buy in the actual market will be smaller. So I really struggle to see how Airbus can hope to go without agreement from either the USA or China. But for the USA to buy in they will want their half of the pie for Boeing and which Congress would survive right now if they showed largesse to the current Boeing crowd? Which leaves China. If the EU/Airbus could come to some agreement with China & whichever state enterprise they choose…..

      • I just don’t see it.

        China is investing in fossil fuel aircraft not Hydo. There is no spin off between military and civilian for Hydro and those two are integral to China ambitions (they need all the help they can get from both sectors as they have not been able to make a modern jet engine yet).

        Forcing a solution in the EU would kill Airbus and the sub EU set of UK, Germany, France and Spain would not go along with that.

        • “”Forcing a solution in the EU would kill Airbus “”

          Jet-fuel only needs to be taxed in the EU same as car fuel, then use the tax money to support LH2 aircraft.

          EU should start with biofuels which don’t add CO2.

        • @TransWorld

          China, apparently, intends to go carbon neutral by 2060, at the latest. Hence, it appears that the only major power holdout will be the United States. By 2040, the EU could very well ban all conventional aircraft using carbon-based fuels, flying in EU airspace. Thus, the EU (and China 😉 ) would essentially force all of the major non-US airlines to purchase the new zero, or near zero, emission aircraft that will ready to enter into service by, say, 2035.

          In a jaw-dropping announcement, Chinese President Xi Jinping said his government plans to boost China’s Paris climate accord target and called for a green revolution, just minutes after US President Donald Trump blasted Beijing for “rampant pollution”.

          Addressing the United Nations General Assembly, Xi reiterated China’s goal of achieving a peak in carbon dioxide emissions before 2030.

          He then announced that his country would effectively balance out its carbon emissions with measures to offset them before 2060, the first time the world’s biggest emitter of carbon dioxide has pledged to end its net contribution to climate change.

          “China will scale up its intended nationally determined contributions [to the Paris agreement] by adopting more vigorous policies and measures,” Xi said, urging all countries to pursue a “green recovery of the world economy in the post-COVID era.”

          Xi used the lectern to call for multilateral action on climate change after Trump called the Paris climate agreement – with nearly 200 signatories – a one-sided deal and criticised China for being the world’s largest source of carbon emissions.


          BTW, do take a look at the chart in the link above:

          Billion metric tonnes of carbon dioxide released between 1750 and 2018/b>:

          USA: 397.0
          China: 214.0

          • We all welcome China’s efforts and wish the US would get back on board too. But the truth is that China emits twice what the US does in a given year, and the difference is still growing. Further the US is on a downtrend trend while China is still increasing, year on year.

            Integrating over 250 years makes it appear to be the reverse, but only because China’s growth has been more recent.

            China has made progress on coal and has invested substantially in nuclear power, which over time will reduce coal further. Coal is far and away the dominant source in China. Coal reduction has also been the reason for US declines, but the shift has been to natural gas rather than nuclear, so there will be less reduction as opposed to nuclear.

          • @Rob

            Of course, you’re only talking about absolute CO2 emissions and not CO2 emissions per capita.

            The biggest absolute emissions come from China and the United States. In terms of CO2 emissions per capita, China is ranked only ranked 47th, at 7.5 metric tonnes per capita. The US is ranked 11th at 16.5 per capita and amongst countries with sizeable populations, has the highest CO2 emissions per capita. India is the third highest country in terms of absolute emissions, but only 158th in terms of per capita output with 1.7 metric tonnes per capita.


            Thanks to the decline of the usage of coal in the U.S. — an industry which incidentally Mr. Trump promised to help out in 2016 — CO2 emissions in the U.S. are slightly down. However, thanks to the horrendous environmental track record of the fracking industry and that industry’s future prospects in the U.S., I would not be too sure if the U.S. greenhouse gas emissions curve would not soon start to flatten out and start to rise again.

            Here’s the good news, such as it is, for the climate: American coal consumption plunged last year, reaching its lowest level since 1975, as electrical utilities switched to cheaper natural gas and renewables. Over the past decade and a half, coal’s collapse has saved tens of thousands of lives nationwide, according to new research, and cut national greenhouse-gas emissions by more than 10 percent.

            The bad news is almost everything else. Outside of the power sector, the country’s planet-warming pollution continued to grow last year. Almost three decades after climate change first became a political issue, the American economy remains a continent-size machine that guzzles fossil fuels and excretes money.


            Proponents of natural gas have said that natural gas is a climate-friendly fossil fuel because it produces less GHG emissions when burned compared to other fossil fuels. According to the Natural Gas Supply Association, natural gas produces half the CO2 emissions of coal. But that doesn’t makefracking clean! The lifecycle greenhouse gas emissions – that is the combined emissions associated with extraction, combustion, and methane and CO2 releases – means that fracked gas can be as dirty as coal.

            Fracking releases large amounts of natural gas — which consists of both CO2 and methane – directly into the atmosphere. In fact, fracking wells leak 40 to 60 per cent more methane than conventional natural gas wells. This happens when water is forced down into a fracking well in order to fracture the rock formations. Methane flows up the well and is released into the atmosphere before it can be captured. The leaked methane is called “fugitive methane” and has been detected using infrared videos. It is identified as different from naturally occurring methane.

            Methane in particular is a very powerful greenhouse gas. It can trap 20 to 25 times more heat in the atmosphere than CO2. Two Cornell scientists who have been studying fracking in the U.S. estimate that in the next 20 years methane will make up 44 percent of the U.S.’s GHG emissions. Along with contributing to global warming pollution, methane leaks kill plants and trees, contribute to ozone formation, and causes natural gas explosions, which have resulted in an average of 17 deaths and 68 injuries per year in the United States alone.


          • If China currently emits “twice what the US does in a given year” then one could argue that it actually under-emitting, seeing as the population of China is four times larger than that of the US.

          • Yes, the per-capita difference is why China was given lesser goals than the US in the Paris accords, as a developing country. Trump objected to that and pointed to the total emissions as an excuse to bail out. That remains an unpopular decision with many Americans.

            Now China has voluntarily said they will exceed those goals, but not exactly how. So we will see what develops.

            China is still a very stratified society. If you look at the per-capita emissions of the cities, they equal or exceed the US levels (hence the smog problems). Rural areas that comprise most of China, are still quite low. As China works to bring resources to rural areas, that will begin to change, and will be a challenge.

            As far as fracking, it is used all over the world and there is the potential for problems to arise, as well as clear examples. In the US, fracking is the primary source of methane release. But EPA studies have indicated it is safe, when conducted properly, and they are working on methods to monitor and contain fugitive methane.

          • @Rob

            Well, in contrast to the U.S. Government, the Chinese Government appears to recognise that global climate change threatens the earth’s ecological safety as well as human survival and development — and therefore, it is one of the biggest threats facing humanity.

            In a little-noticed speech this week, China permanently changed the global fight against climate change

            China will scale up its Intended Nationally Determined Contributions by adopting more vigorous policies and measures. We aim to have [carbon dioxide] emissions peak before 2030 and achieve carbon neutrality before 2060.”

            Xi Jinping’s speech via video link to the United Nations General Assembly on Sept. 22 was not widely trailed in advance. But with those two short sentences China’s leader may have redefined the future prospects for humanity.

            This ought to give Americans from all sides pause. If the Republican China hawks mean what they say, it surely should be puzzling to them that Beijing, which they accuse of foisting the climate issue on the world to hobble America, is now making a huge and unilateral commitment on decarbonization.

            But Xi’s move should also be a wake-up call for advocates of proactive climate policy on the Democratic side. Against the backdrop of climate negotiations in the Bill Clinton and Barack Obama eras, their approach tends, in its own way, to be highly transactional. The conceit that one can still hear from veterans of U.S. climate diplomacy is that the world is waiting for America to come back to the table and that no big deal like that at Paris in 2015 is conceivable without the United States.

            But 2020 is not 2015. The sobering truth is that neither the EU nor China is any longer conditioning its climate policy on the United States. If you are serious about the issue, how could you? If Washington does come around to supporting a Green New Deal of the Joe Biden variety, that will, of course, be welcome. But in light of America’s cavalier dismissal of the Paris agreement, even if a new administration were to make a new and more ambitious round of commitments, what would that amount to? So long as the basics of the American way of life remain nonnegotiable and climate skepticism has a strong grip on public opinion, so long as the rearguard of the fossil fuel industries is allowed the influence that it is, so long as one of the two main governing parties and the media that supports it are rogue, America’s democracy is not in a position to make credible commitments.


          • @Rob

            Also, you didn’t mention indirect CO2 emissions, or embodied carbon emissions, and its impact on overall US and China emissions of carbon.

            Over the past decade, both the United States and Europe have made major strides in reducing their greenhouse gas emissions at home. That trend is often held up as a sign of progress in the fight against climate change.

            But those efforts look a lot less impressive once you take trade into account. Many wealthy countries have effectively “outsourced” a big chunk of their carbon pollution overseas, by importing more steel, cement and other goods from factories in China and other places, rather than producing it domestically.

            Britain, for instance, slashed domestic emissions within its own borders by one-third between 1990 and 2015. But it has done so as energy-intensive industries have migrated abroad. If you included all the global emissions produced in the course of making things like the imported steel used in London’s skyscrapers and cars, then Britain’s total carbon footprint has actually increased slightly over that time.

            The new report, which analyzes global trade from 15,000 different sectors — from toys and office equipment to glass and aluminum — builds on previous academic research to provide one of the most detailed pictures yet of the global carbon trade.

            Not surprisingly, China, which has become the world’s largest emitter of carbon dioxide, remains the world’s factory. About 13 percent of China’s emissions in 2015 came from making stuff for other countries. In India, another fast-growing emitter, the figure is 20 percent.

            The United States, for its part, remains the world’s leading importer of what the researchers call “embodied carbon.” If the United States were held responsible for all the pollution worldwide that resulted from manufacturing the cars, clothing and other goods that Americans use, the nation’s carbon dioxide emissions would be 14 percent bigger than its domestic-only numbers suggest.


          • This argument would make sense if the importing countries had authority over the emissions of exporting countries. But they don’t. Each country is responsible for their own emissions, and must factor that into their economic decisions. Thus the notion of “embodied carbon” implies a legal & jurisdictional framework that doesn’t currently exist.

            If you wanted to impose a tariff structure that transferred the emissions burden from the producing country to the purchasing country, that could be done. But then the purchasing country would likely pull back production so they could manage it themselves. And with it would go the economic advantage to the producing country, which isn’t a desirable outcome for them either.

          • @Rob

            The European strategy to reduce greenhouse gas emissions builds on the actualisation of technological progress; countries should catch up and/or advance their economy-wide production system via more efficient, that is, less CO2 emitting technologies.

            Of course, one key issue in this respect is the carbon leakage effect which occurs when a country reduces its greenhouse gas emissions by substituting own production of carbon intensive goods with imports from another country.

            Several solutions to the carbon leakage problem have been proposed. Here’s one proposal:


            Climate effects of unilateral carbon policies are undermined by carbon leakage. To counteract leakage and increase global cost-effectiveness carbon tariffs can be imposed on the emissions embodied in imports from non-regulating regions. We present a theoretical analysis on the economic incentives for emission abatement of producers subjected to carbon tariffs. We quantify the impacts of different carbon tariff designs by an empirically based multi-sector, multi-region CGE model of the global economy. We find that firm-targeted tariffs can deliver much stronger leakage reduction and higher efficiency gains than tariff designs operated at the industry level. In particular, because the exporters are able to reduce their carbon tariffs by adjusting emissions, their competitiveness and the overall welfare of their economies will be less randomly and less adversely affected than in previously studied carbon tariff regimes. This beneficial distributional impact could facilitate a higher degree of legitimacy and legality of carbon tariffs.

            The climate effect of unilateral carbon pricing is undermined if emission-intensive production is relocated to less regulated jurisdictions, so-called carbon leakage. Seminal theoretical papers by Markusen (1975) and Hoel (1996) suggest that a region should supplement its unilateral carbon pricing with border carbon adjustments (BCAs). BCAs are tariffs designed so as to tax, equally to domestic emissions, the carbon emissions directly and indirectly embodied in imports (carbon tariffs), combined with rebates of emission payments for exports from the unilaterally regulating region. Markusen (1975) and Hoel (1996) show that the most cost-effective BCA system for reducing carbon leakage is one that incentivises foreign producers to abate until their marginal abatement costs equal the carbon price of the unilaterally regulating region.

            Although carbon tariffs have not been implemented so far, they are assessed and debated in several OECD countries. In the US and Australia the discussions have been closely linked to proposed cap-and-trade systems. The EU, that already has a cap-and-trade system, has been nearest to a system taxing imports by its attempt in 2012 to incorporate into the EU Emission Trading System (ETS) all flights to and from EU airports (Directive 2008/101/EC). The plan has been put on hold due to fierce opposition from the international aviation community and major non EU countries such as the US and China (Ireland, 2012). The ongoing political debate on measures for pricing emission from aviation at a global scale highlights the importance of distributional and legal issues at stake.


        • There might be a military connection for LH2 powered Aircraft as “Loyal wingmen” and “One time use” Aircrafts come on-line needing very cheap engines where LH2 cooling of the core engine can make it much easier building low cost unmanned fighter jet engines.

  6. Sinnett’s statement recognizes Boeing weak position regarding new disruptive technology. That said, he may be acknowledging real risks that should go into any business strategy.

    Hydrogen is much more demanding to work with than kerosene. It alway leaks. This is well known to laboratory technicians around the world, and to anyone whose car battery has caught fire and injured them, or destroyed their car.

    As Scott says, hydrogen needs to be safe and reliable in Siberia and Algeria. Really, it must be safe everywhere, every day.

    • I have not a clue where Boeing is really going (supposedly T-7 is based on disruptive)

      But disruptive in aviation power sources is not in the cards.

      Production maybe (stay tuned), 3D printing yes, power, no.

      Flying is such a fraught area, when a 737 is competitive with a much newer A320 (and even can see the taillights of an even newer A220) it tells you some improvements (aerodynamic and fuel) are two huge hurdles.

      Disruptive is a cool phrase to use, but some tech is just about as good as it can get.

      Take a Water Pump. You can refine the daylights out of it, but there is no technically that replaced an impeller on a centrifugal pump in a cast iron housing.

    • Wasn’t Sinnett the one who talked with airline pilots after JT610 and came up with stupid excuses why Boeing did this and that. Then he was asked what will be if the MAX crash again and he answered it would be a disaster.
      To keep Sinnett to speak Boeing’s words to the world now is a disaster too.

  7. Aircraft are one of the last places one should look for eliminating CO2 emissions. They are only something like 2% of emissions globally (globally is the only metric that matters with CO2 and other greenhouse gasses).

    The magnitude of the greenhouse gas emissions you can get per unit of money/effort is how you decide what to do. Eliminating aviation today (just hypothetically) would not have a meaningful effect on climate change.

    The world needs to eliminate thermal coal by replacing it with solar, wind, storage, nuclear and a little gas for meeting peaks. That makes a real dent in emissions at a FAR lower unit cost than going to H2 in aircraft, and there are many more ways to reduce greenhouse gases (including in aviation) that are far more cost effective than H2 aviation.

    • Yes, and that’s why I see this initiative as more of a research program, to explore how it could be done within aviation, and the true costs and capabilities. It might also result in a commercially viable LH2 regional aircraft, or at least a practical design for one.

      The reporting is that the EU (or at least France) has in mind an investment of $81B for carbon reduction. Of this, only the first $15B have been announced. Of that, we might expect $5B to go to Airbus, with the rest going into infrastructure. The Airbus amount could go higher if there is early promise.

      So in that sense, $5B out of $81B might be appropriate for aviation, if the rest goes into terrestrial improvements. We will have to see what develops. I would say more than $5B, without reasonable certainty of success in the market, would not be practical, as the funds are clearly better invested in terrestrial sources, as you and others here have said.

    • Dan F:

      Agree. Some technology you can see a huge promise even if it takes time to develop it (3D printing)

      What would it cost to get the Indonesian’s to stop burning? I know its not an end all, but a help.

      Or to buy out Brazilians from the Rain Forrest?

    • @ Dan F.
      You are, of course, completely correct…but try convincing vehemently anti-aviation greenies of your arguments and see how far you get. In Europe at least, the greenie mob would like to kill aviation as quickly as possible.
      With a single occupant, the average midsize car produces 2-3 times as much CO2 per km (per passenger) as a modern airplane…but you don’t hear that type of comparison in the media. And shipping produces about as much CO2 as aviation, but you don’t hear much about that either.

    • This is an answer to thousands of public comments that Boeing & FAA officials need to fly the MAX before anyone else does. The implication being that they don’t care about pubic safety. It’s more about responding to those statements and showing that they have a personal stake in the outcome.

      It won’t make the MAX any safer but it demonstrates commitment to being sure it’s safe for passengers. I give Dickson credit for following through on his promise. It’s good that he and Elwell have a 737 rating. It’s also good that they will go through the new training personally, they will have a first-hand understanding of the process.

      The JOEB training results will be posted by FAA and there will be a 15 day comment period, so that will be interesting to see.

      Patrick Ky said today that the EASA flight testing and JOEB review have gone well, and the MAX is on track for November recertification in the EU. Canada will follow, and I suspect most of the world will as well. No word from China but we know Air China is updating their MAX fleet, based on their AD comments.

      • Public comments wanted those people on a MAX with MCAS 1.0.

        Dickson flying is just a stunt. Anything goes wrong and the other pilot will pull it out.

        I don’t expect it to now.

        But it does not address the raised concerns on the Manual Trim as well as the cockpit mess the 737 has become.

        The good news is Canada, EASA as well as US non Boeing and non FAA continue to push for better.

        Any new model should meet all the latest specs, not just cherry picked ones. If it cost too much then its time to replace it.

    • As if a one-off PR flight by a Boeing executive has anything to do with “being sure it’s safe for passengers”.
      The MAX managed to take off and land for months (in some cases, just about) before the LionAir and Ethopian crashes occurred. A single benediction from a Boeing suit doesn’t have any substance when it comes to statistics.

      • Bryce, the FAA was accused of not being attentive enough on the MAX. You don’t get much more attentive than taking the controls yourself, to see for yourself.

        I’m sure this won’t be a joy ride, they’ll be running through the MCAS scenarios and checking their work in the real world, on the real aircraft. It lends weight to their stance that they know first-hand that the problems are fixed and the MAX behaves properly.

        • What would build confidence is to reform FAA and Boeing so this does not happen again on the type of implementation that is known to cause unsafe aircraft.

          Focusing on the MAX is a slight of hand, fix the obvious issues and hope the others don’t strike.

          Boeing conti8nues to pay lip service but has not made any moves that correct the underlying cause. One simple move like asking congress to return ODA to its former status would be one move.

          Fixing FLCH Trap would be another.

          Reporting on how the Flight Simulators lost their Fidelity with regards to Manual Trim would be another one. There is a whole story of a corrupted process in the Flight Simulator.

          Having worked closely with Flight Sim people, I have no idea how that could have occurred. I was through one fidelity issue that was coming from my side of the equipment and it came close to being shut down.

          They do daily Fidelity Tests and also monthly or quarterly tests that are data captures sent to the FAA.

          Talk is cheap and actions are what counts. Or you can go with the Nigerian Prince thing and gives someone your lives savings.

          Verify, then Trust.

          • TW, we’re back to loop and repeat mode here again.

            We all know the reason for the simulator error was not including the range of forces that could occur above the MAX speed limit for altitude. In normal flight, the sim was correct.

            Since then the simulators have been corrected, tested and verified, and the MAX has been tested and verified by all the major regulators and found compliant. That is the truth as has been established by independent observers.

            The FLCH mode “trap” resulted from pilots entering the target altitude as too low a number for the auto-throttle to resume after descent, sometimes even zero. In that case, the auto-throttle goes to idle for quickest descent, which is the correct behavior for FLight CHange mode.

            The proper mode for landing approach is Vertical Speed, which uses pitch to control descent and throttle to control airspeed. So pilots using the recommended method did not encounter the “trap”. Also pilots entering the target altitude as a safe number did not encounter the “trap”. All of which is covered in training.

            As with the MAX, the NTSB pointed out that assumption of pilot behavior is fine, but the actual behavior of pilots indicated they needed protection from this error. So that will now be added. And that is also the truth.

            Legislation is pending that will roll back some aspects of ODA, and Boeing has not opposed it. Boeing has been fined by FAA for actions inconsistent with ODA principles, by a group of managers, and Boeing has not opposed it.

            The theme here is a rejection of what has been shown to be true, in favor for what one prefers to believe to maintain one’s opinion. And that is also what drives the repetition after resolution.

            In this case Dickson, Elwell and FAA are doing a right and good thing by flying the MAX, and that is actually what bothers you, as it’s not consistent with your opinion of them. So it has to be derided and put down. Thus we’ll let this go, as we always do, because it has no basis.

          • “Thus we’ll let this go, as we always do, because it has no basis.”

            There’s that “we” again. Who is it supposed to be this time?
            – Do you pretend to speak for all humanity?
            – Are you authorized to speak on behalf of all commentators here?
            – Is it perhaps the Royal Plural?
            – Or are you speaking on behalf of Boeing?

            We are indeed “back to loop and repeat mode here again”.

          • Bryce, the “we” is a general inclusive that suggests that “we” have a common factual basis of evaluation & understanding. You don’t wish to be included in that group, preferring your own opinions instead, hence the objection to inclusion and the term “we”.

            It’s notable that the objections to “we” only come from people here who stick to their views in the face of all evidence to the contrary. There are only a few, and not surprisingly, they are also the ones responsible for the derisive commentary. That has its roots in the same elevation of opinion over facts. It also serves to distract both from the elevation and the facts, which I notice you do not address here.

            One more point on the FLCH trap, I asked about this in pilot forums. One person pointed out that using FLCH on approach and setting the target altitude to zero, was equivalent to commanding the aircraft to perform a dead-stick landing. That might work in some cases, and having your hand on the throttle (as recommended) would allow you to override in other cases. But sooner or later, you’d be caught out by it. That’s why it was not recommended in training.

            Now, even in FLCH mode, the auto-throttle will provide minimum speed protection. But it’s still not recommended for approach.

          • “”What would build confidence is to reform FAA and Boeing so this does not happen again on the type of implementation that is known to cause unsafe aircraft.””

            Add EASA to them if they certify MAX.
            It seems I will never fly again if this is a corrupt clown show.
            EASA can’t even flight test alone, need babysitters.

          • @ The Voice of Boeing
            “It’s notable that the objections to “we” only come from people here who stick to their views in the face of all evidence to the contrary.”

            You like to see it as “evidence”, but others see it as “so-called evidence”…perhaps because they look at the problem more broadly, and/or because they’re a little less puppy-dog-like in their enthusiasm to see the MAX up in the air again at all costs.

            For some people, MCAS is only a detail: its main importance is the underlying shortcut-taking attitude that it revealed…an attitude that also underlies the whole spectrum of issues with the Dreadliner. Although MCAS may be patched-up, the underlying attitude hasn’t evaporated. There is already a list of issues in addition to MCAS, but (many) others will doubtless reveal themselves once the MAX starts flying again. The basic tenet remains: a highly-compromised dinosaur — a knee-jerk reaction to Airbus’ announcement of the NEO — thrown together and rushed to market so as to start generating profit a.s.a.p.

            That’s one possible reason why your infinite confidence (perhaps gullibility?) isn’t shared by all.

          • @ Leon
            I suspect that EASA’s hands are somewhat tied by political considerations: if EASA makes a meal of the MAX, then the FAA may (be instructed to) similarly impede certification of the A321XLR, or start bitching about the Trent engines on the A330 NEO, for example.

            The reaction from the CAAC will be interesting, since China doesn’t (yet) have any aircraft flying outside China, and is very ticked off by the Trump administration. Some people opine that CAAC certification is a done deal (because of purported recent queries by a Chinese airline regarding FAA-mandated changes to the MAX), but I prefer to see how the dice actually falls.

          • Bryce, with these posts, you prove my points. The adherence to your opinion over fact (as now determined by worldwide regulators). The need to use derogatory language to put down others and opposing views. All necessary to avoid accepting the truth.

            It’s all here, once again, and it undermines your positions, whether you realize it or not. Your true nature and motivations come out, and they aren’t pretty.

            You should have learned by now, bullying doesn’t work here. You can’t establish the merit of your views by deriding the views of others. No one here will respond to that behavior. Facts, yes. Rational arguments, yes. Insults, no. Name calling, no. Personal agendas or axes to grind, no.

          • “”if EASA makes a meal of the MAX, then the FAA may (be instructed to) similarly impede certification of the A321XLR, or start bitching about the Trent engines on the A330 NEO””

            If the XLR is dangerous (I doubt that, it’s fly-by-wire) it should not fly.
            If Trent is dangerous it should not fly too.
            I won’t buy VW, Audi, Porsche, Mercedes too.

  8. I find it strange that Sinnett discusses safety as the main reason not to look to a change of technology.

    Firstly, the number of accidents due to fuel issues is very low in the overall safety record. Whilst it is true that introduction of a new power train technology could lead to increased systems failures or fuel issues over a period, issues like controlled flight into terrain and loss of control in flight (top two fatal accident categories) are absolutely unaffected.

    His response comes across to me as really missing the big picture and pointing to safety to justify inaction on decarbonisation.

    • Somebody hasn’t heard of the Hindenburg.

      Or China Airlines 120

      Or Aeroflot 1492

      Or American 383

      Or Delta 89 (if this counts as a “fuel issue”)

      Or any other crash where the impact was survivable but the post-crash fire wasn’t.

  9. Production of LH2 by electrolysis is a (very) endoergic process; logical, seeing as the LH2 has such a high energy density, and has to get that from somewhere.

    Extraction and underground storage of atmospheric CO2 from (synthetic or algal) hydrocarbon combustion is also an endoergic process.

    Thus arises an interesting question: which of these processes is less endoergic (for an equivalent CO2 volume), and which is more readily implementable in terms of technology, societal acceptance and costs?

    Control theory is rife with examples where, instead of trying to prevent something from happening, one instead opts to let it happen and then mitigate the effects thereof. That might also be the best approach in terms of CO2 emission.

    • Lost me on that one.

      Control Theory is a wide open area, never ran into a part of that which allowed an excursion (yes it allows very short ones) that does not then clamp the oscillation tightly.

      Have to spell that our where in PID this means.

      • For example:
        If you want to address positioning errors due to particular vibrational modes in a machine frame, then you can:
        (1) Attempt to make the frame (infinitely) stiff at certain frequencies; OR
        (2) Allow the frame to do its thing, and counteract the resulting positional errors using loop-driven corrective actuators.

        It’s easy to conceive a similar analogy w.r.t. temperature control, for example.

    • Well, if we do get nuclear fusion going, LH2 production effectively becomes “free” and pretty clean. And we could also pull CO2 from the atmosphere. Without fusion, we’re going to have to get judgments such as your question right, otherwise we’d just be making things worse.

      • We’re going to have to wait until 2035 before ITER even starts fusion reactions, and — even then — it will be using the relatively sub-optimal deuterium-tritium reaction.
        But you raise a valid point: is it better to invest in LH2 aircraft technology, or to would it be better to spend that money on additional fusion research, e.g. w.r.t. stellerators as an alternative/supplement to tokamaks.

        Getting viable fusion going will probably be humanity’s greatest technical achievement…and it’s needed at a juncture when we’re rather short on time.

      • The killer issue with fusion is that for the small scales we are able to accomplish it, the radiative losses are too large to retain enough energy for ignition. A star doesn’t have this problem because it has many layers above the fusion layer, to reflect and contain sufficient energy for sustainment.

        To replicate that, we either need materials with astronomical thermal properties, or we need a force like gravity that can contain massless energy-bearing particles (radiation). Conventional electric and magnetic fields won’t serve that purpose.

        In the meantime, we must invest large amounts of energy to sustain the losses. Or we can do brief fusion “shots” that use less energy, but have only a small excess, them gather the excess over a large number of shots. But either way, the net harvest is only a small fraction of the energy released, so there would be a very large thermal loss. That might be put to use in other ways, and perhaps would be needed to make fusion cost-effective.

        But all of this is still a ways off yet, if feasible at all. I don’t think we can look to fusion to solve the current carbon problem.

  10. Here’s a very upbeat “general press” article on that hydrogen-fuelled Piper M that did a short test run this week in the UK.
    The article (conveniently) doesn’t touch on production/distribution of LH2.
    Note, also, the extreme optimism contained in the following sentence: “ZeroAvia says that without any new, fundamental science, hydrogen-powered craft already have the potential to “match the flight distances and payload of the current fossil fuel aircraft” in the future.”

    Certain elements of the general public reading this type of overly upbeat article will tend to point to any delay in introducing LH2 aircraft for mainstream commercial aviation as evidence of vested interests by the industry, and profit-before-environment resistance to change.


    • It seems H2 is not difficult to use. Why auto industry didn’t come up with it long time ago. Now they lose many jobs because e-cars have less parts.
      Seems to be a greedy situation same as Boeing too, they just keep selling their trash.

      • Use is not the issue, natural gas is used for piston and turbines.

        Its the fuel tank and piping and support system on an aircraft. BMW (Mercedes?) years ago did a H2 car. Its range was all of 70 miles. High pressure tank. No trunk space (taken by tank).

        It take power to get H2. That means fossil fuels as there is no where near enough Wind or Solar to do the job (and its doing another job already)

        At what point does carpeting the world with Wind Turbines meet its limits?

        If there was easy answers it wold have been done.

        • The BMW was 10 years ago. It was an LH2 and normal fuel Hybrid. So LH2 was only attached which won’t give good results.

      • This is also a fuel cell type, not listed was the capacities taken up and its a non direct burn which seems to be discounted as feasible (ie H2 Electric vs H2 Gas Burned in a Turbine or piston).

        So even you get 250 miles, all it carries is a pilot.

  11. A question:
    If an oxygen supplier such as Air Liquide were to decide to build an electrolysis plant — powered by “green electricity” — to produce bottled O2 (for industry/healthcare) and LH2 (for the existing public-transport usages in Europe), how would the unit production costs of each of those products — produced via this electrolysis route — compare to the unit production costs of O2/LH2 produced by existing techniques?

    • No idea.
      What they are planning to do here in Germany is to use excess energy from wind turbines ( that would otherwise overload the grid ) to produce “green” H2.

      Causal issue is that the southern Bundeslaender have been less than active to expand their grid carrying capacity as that would move quite a bit of tax (“Gewerbesteuer”) income north.

      • It is, of course, a great idea to use “excess” electricity to produce LH2, but I presume any industry using such electricity would have to pay the going rate? In that context, I’d love to know how commercially viable it is to produce LH2 and O2 via the electrolysis route. One assumes that this route will obviate any present-day, non-electrolysis methods of producing bottled O2.

        • “such electricity would have to pay the going rate?”

          He, he.

          Much back and forth going on if such use of grid electricity has to pay the eco levies applicable or not.

          With an interesting hitch in sight:
          if power used for H2 production is exempted any grid source ( wind, solar, COAL, OIL, NUCLEAR ) will be exempted when used to produce H2. this is what minister Altmaier would like to push. He is more of a big industry lobbyist than loyal government.

          Preferable would be an exemption for alternate energies that can not be fed into the grid.

          What I find distasteful in this context is the fact that we dance around artificial intractabilities instead of fixing things in a sensible way at the core. Physics! not graft.

  12. How can anyone believe hydrogen powered aircraft is practical?
    The concept is only a way to cover government subsidy.

  13. Before we get too carried away we should take a look at the integrated production, transport and storage of hydrogen. Early cars obtained gasoline in glass containers from a local drug store!

  14. The BMW LH2 was reported 14 years ago, so the tech is even older.
    BMW must have used a cryo tank with a combination of load factor and pressure because it took 17h for an H2 blow off start.
    The H2 blow off was reported to be 0.010-0.012kg/h and took 9 days.
    9days x 24h x 0.012kg/h = 2.6kg
    Less than 3kg is not much LH2 if the blow off rate is linear.
    The tank was kind of big, maybe 50L, its weight was reported to be 129kg. That’s terrible but also long time ago.

    Much better is Ariel’s 6L/2kg example.
    A plane wouldn’t need 17h for a blow off start, so less pressure, higher load factor. After a flight the load factor is already much better, so no need to unload the tank always. With the much better surface/volume factor there’s less pressure to blow off. Less pressure is also safer. Pressure is only needed to support the tank stucture.

    So how heavy must a tank really be, the isolation seems not to be a problem. Also the surface/volume factor is better than on a jet fuel plane. The LH2 tank can be heavier than on a jet fuel plane but the lighter LH2 makes the difference. The weight shouldn’t be a problem. Only more fuselage space is needed.

  15. As one of the hundreds of thousands of Americans having their communities destroyed by FAA NextGen, electric aircraft can’t come soon enough. Though due to the battery weight problem (among other problems), I realize it won’t be anytime soon. The airline industry has been kicking the can down the road for some time on the carbon emissions problem (Delta’s recent announcement is one of the most egregious examples of greenwashing I think I’ve ever seen). I want to be a supporter of the aviation industry, but the FAA’s and the airline’s actions over the past few years make it really, really hard. http://www.nextgenrelief.org

    • Alison, you may already know this, but the FlightAware app reports in real-time the information of aircraft flying overhead. Also the Airnoise app files noise complaints for you based on your location. Another app called Explane records the actual decibel level in a world-wide database, along with the flight information.

      The NextGen system now uses GPS waypoints for approach, that’s why the flights tend to get concentrated over specific areas. Also the descent paths & glide slopes are now also standardized to optimize fuel burn.

      Believe it or not, the optimized glide path also minimizes noise of each aircraft, but if there are more of them with constant repetition, or at lower altitude, that isn’t at all apparent. Another issue is that aircraft separation can be reduced, but that too adds to the total noise.

      We lived just off ORD for several years. If the wind was right, the aircraft descended overhead at a few hundred feet. You got used to pausing conversations rather than shouting. Not to mention the shadow passing over you.

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