MTU gets support from Pratt & Whitney to develop the WET engine

By Bjorn Fehrm

November 29, 2022, © Leeham News: MTU and Pratt & Whitney presented an EU Clean Sky project today where they will develop an advanced engine concept based on the Pratt & Whitney GTF. The project is called SWITCH, an acronym for Sustainable Water-Injecting Turbofan Comprising Hybrid-Electrics.

There are participants from 11 countries in the project, among them Pratt & Whitney’s sister company Collins aerospace, GKN’s Swedish part, and Airbus.

The engine, which has a mild parallel hybrid architecture, extracts more energy from the turbofan fuel by driving the core exhaust through a vaporizer, where it recovers more heat from the core exhaust, Figure 1. Water from the exhaust, extracted from the core exhaust in a condenser, is heated to steam by the vaporizer and then drives a steam turbine that co-drives the fan. The steam is finally injected into the combustor to lower emissions.

The WET cycle will gain about 10% efficiency compared to today’s GTF. The concept also has a hybrid part which is primarily used for a low-emission taxi.

Figure 1. The architecture of the SWITCH engine. Source: SWITCH.

The SWITCH engine

The SWITCH project is a European Clean Sky project with several participants, Figure 2. MTU, as a European company, is the lead. In total, Industry partners and Universities from 11 countries are involved in the project.

The first part, between 2023 and 2025, develops the WET engine components and further develops the hybrid technologies that Pratt & Whitney/Collins worked on in the STEP project and the regional turboprop demonstrator with De Havilland Canada.

Figure 2. The SWITCH principal project members and the goal for Phase 1 of the project. Source: SWITCH.

WET the main innovation

The main innovation in the project is the WET engine principle that uses the water created in the combustion process of a gas turbine to enhance engine efficiency. The combustion gases are routed to a Condensor placed in the bypass stream, where the water is condensed and extracted, Figure 3.

The water is then routed to the Vaporizer, where the heat from the core exhaust converts the water to steam that drives a Steam turbine attached to the low spool of the engine. The core’s remaining heat in the exhaust is thus used to add power to the low spool and the fan. The more complete extraction of heat from the core’s exhaust gases increases the engine’s efficiency.

Figure 3. The WET enhanced turbofan components. Source: SWITCH.

After the steam turbine, the water is routed to the combustor as steam, where it’s injected to lower the combustion temperature. The lower combustion temperature reduces NOx creation by up to 80%. The mass increase from the water gives the combustion gasses a higher energy level so that more power can be extracted from the turbines.

The concept also lowers contrail generation as the amount of recirculation can be managed, and any excess water can be dumped into the atmosphere after the condenser.

A mild hybrid

The hybrid part is an add-on energy conservation part. During the ground stop, batteries in the fuselage are charged. The energy is then used to drive the fan via a motor generator working in parallel on the low spool, Figure 4.

The taxi and takeoff will consume the energy stored in the aircraft battery; therefore, the function during the rest of the flight is to assist the engine during power changes (by allowing more aggressive scheduling of the compressors) with the remains of the battery energy.

Figure 4. The hybrid parts of the SWITCH engine. Source: Switch.

The assistance during takeoff is modest as the spool powers are north of 20MW each in this phase, and the motor generators are 1MW (low spool) and 0.5MW (high spool).

At cruise, the spools need between 5 to 7 MW each, dependent on the engine variant. The motors could then contribute up to 20% of the booster/fan shaft power, but I see no chance of having batteries with enough energy so these can contribute in these phases.

We need a minimum 1,000 kWh battery for taxi and takeoff, and it would weigh about 4t, so a battery that would have energy for climb and cruise is out of the question (it would weigh more than the whole propulsion system).

Couldn’t the gas turbine charge the battery via the motor generators? Yes, but as discussed several times, charging a battery with the aircraft’s gas turbines make little sense. You add over 10% of losses in the chain generator-power distribution-battery-power distribution-inverter-motor-fan compared with driving the fan directly.

In effect, the hybrid then increases the fuel consumption and CO2 emissions for the aircraft compared with using the gas turbine to do the job directly.

Aircraft integration aspects

The hybrid part requires a power distribution system in the aircraft and a propulsion battery, Figure 5. Airbus is looking after the integration aspects of these parts of the project.

Figure 5. The integration of the SWITCH engines in a single-aisle aircraft. Source: SWITCH.

The mass of the GTF engines would increase from 3t to about 4.5t when WET is integrated. So the engine mass goes from 6t to 9t. The hybrid part adds another 5t to this figure, dependent on the battery size.

Energy efficiency and emissions

The WET technology is projected to save about 10% of fuel consumption and, thus, CO2 emissions. It also lowers the NOx emissions of the engine by about 80% and reduces contrail generation.

The ambition of the project is to save up to 25% fuel and, by it, CO2 emission compared with today’s GTF turbofan that powers the Airbus A320/A321.

Where the other 15% comes from is for the project to explain. It can’t come from a hybrid part that is active during taxi (where it provides all necessary fan power) and takeoff, where it contributes about 5% of the needed power to drive the compressors and fan.

Conclusion

The WET engine concept is an interesting idea, equally applicable to Jet-A1, SAF, or hydrogen-burning engines.

What about the hybrid part? It makes sense to include it in a research project where the technology can be brought forward and knowledge gained. As presented, it doesn’t make sense for a serial application.

141 Comments on “MTU gets support from Pratt & Whitney to develop the WET engine

  1. Flying steam turbine, and flying condensers, and flying vaporizers?? Whoa.

    * 11.1% higher overall efficiency (1/0.90), with a stretch goal of 33.3% higher overall efficiency (1/0.75)
    * 80% less NOx
    * Reduced contrails

    How come we took so long to discover aero steam?

    • > How come we took so long to discover aero steam?

      Because there was lower hanging fruit… bigger fans, higher temp, optimized airfoils, tighter tip clearances etc etc.

      • Water injection has been used in the past in the early days and when proposed in more modern times the Airlines rejected it.

        That balance between benefits and Return and more complexity tends to be much higher failure and maint let alone overhaul.

    • I have to wonder how much the water and the batteries add to the weight of the aircraft. I don’t believe you will have room for very many passengers after you fill the aircraft with all of this. Then you have the additional maintenance and charging costs added in . A trip across the state wod be 5000.pp usd.

      • That is the issue, not can you make it but its economics

        Solar Power is a great thing but there are not any current (pun intended) ways to store it and at night it quits.

        That said, the daylight hours are the most intense demand period with industry, office and home AC being huge users. So Solar if it simply replace part of the AC residential use has a huge impact.

        There is a 2nd use Solar could be put to, that is a system with batteries (most have that) can for a short time drop off the grid and sustain essential in a house.

        That on a rotating basis with home owner buy in for a rate reduction could carry a night time load.

        As this is a purely Aviation forum, the focus is on Aviation naturally, but the issue is a whole planet solution and rather than shoot for pie in the sky, implement many solutions on the problem and then Aviation just needs to be responsible, any Aviation solution solves a small part of the issue and its solutions don’t roll over into larger ones.

  2. I wonder if the real goal of this is to be a hydrogen-fueled engine that deals with the contrails concern.

    I suspect there is some heavy marketing spin on this with the engine itself being 10% more efficient but much of that will be lost lugging around 7t of extra engine weight and battery.

    • Yeah. Single aisle airplane.
      Avionics just a massive amount of weight to compensate. Open to the idea, but difficult into thinking it’s anything else.
      Best

    • Yes, too complex and heavy to possibly be worth the benefit. Ultrafan or possibly propfan make more sense.

        • Ultrafan as I understand it has a better (hotter) core with more advanced materials, and even higher bypass ratio (+/-15/1) and possibly eventually some degree of variable pitch for the fan.

  3. Seems the perfect solution for hydrogen propulsion:

    The condenser may be the only solution to address any environmental concerns due to contrail formation with the water vapor rich exhaust of burned hydrogen. If it can also be used to boost thermal efficiency via steam injection it would be a win-win solution.

    The hybrid part makes no sense with batteries, but in a hydrogen powered aircraft with a fuel cell APU…

    No wonder why Airbus is involved.

  4. Smells like PR + Hopium to me.. we’ll see how it goes.

    Also, see Jevon’s Paradox.

    • @Bill7
      You do know these exact same sentiments were said when President Kennedy made the commitment for us to put a man on the moon and return them back safely in less than 10 years?

      • Airdoc:

        Yep, lots of money thrown at it and it was successful. There are no people on the moon today.

        No return on it despite the recent flailing of NASA.

        China will be the next country to put people on the moon and they will stand around and look at each other in the lander when no one is looking and, well dudes, now what?

          • Would be interesting to compare
            Apollo
            Shuttle
            Ares/Orion/…
            in inflation corrected numbers.

            again: Apollo supports my argument of such
            US projects needing external help for a sane framework.
            Another downer is organizational deterioration.
            see Pournelle’s law on bureaucracies

        • @TW

          Thank you.
          Yes it cost a ton of money, but this wasn’t my point. The point I’m eluding to is what the technology gained from the space programs did for future generations.

          Vietnam cost a ton of money and much much more.
          What Pedro said noted below.

          • Nothing new under the sun. U.S. repeated its Vietnamese venture from 2001 to 2021.

          • Airdoc:

            I wont respond to Pedro, its both far off topic and political and he should know better.

            Yes, its a good point and worth remembering at the time that The Moonshot did indeed return tech to the economy. It would be good to get a true breakdown of what that was and would it have come anyway?

            That said, its now the same o same o and NASA can’t get its act together (multiple failures).

            Arguably we are reduced tech as its back to capsules in place of the vastly more capable Space Shuttle.

            Whats the mission? And what is the cost and is there any return? Money is no longer free and easy. Personally I think its now a death throes of NASA thrashing around trying to be relevant when its no long has a mission and is money down the drain.

            Mars even if it could be done is not sustainable and another one and done. There is nothing there other than its there but then again so is Pluto.

      • I don’t think your analogy holds, Airdoc. This WET program
        *might* deliver a small increase of efficiency, disregarding
        for the moment its increased weight, complexity, and maintenance costs.

        It’s not exactly a “moonshot”, and I question why this incremental approach is even getting research funding,
        what with high-tech “green energy” sources which are said to be right around the corner?

  5. > In economics, the Jevons paradox (/ˈdʒɛvənz/; sometimes Jevons effect) occurs when technological progress or government policy increases the efficiency with which a resource is used (reducing the amount necessary for any one use), but the falling cost of use increases its demand, negating reductions in resource use. The Jevons’ effect is perhaps the most widely known paradox in environmental economics. However, governments and environmentalists generally assume that efficiency gains will lower resource consumption, ignoring the possibility of the effect arising.. <

    https://en.wikipedia.org/wiki/Jevons_paradox

    • Like people who buy a hybrid or electric car and then drive twice as much “Because it’s so cheap to operate!”.

      • The hell of it is, Honda made an optimized internal combustion Civic model ‘VX’ that outperformed
        any hybrid in full-cycle costs (and drove great!).

        It was discontinued here in the US due to lack
        of demand, they said. Maybe it didn’t have a hybrid’s
        “Groovy Green” factor with a certain socially-conscious set.

        • It was a tiny light car and not relevant to today’s U.S. market. They also made the Insight hybrid which was a bunch more efficient.

          • > It was a tiny light car and not relevant to today’s U.S. market. <

            Have you driven a Honda Civic VX? I have; it is not "tiny", seating four persons with adequate room for all, and in some style. As for "not relevant to today's US market you are right: that "market"
            consists of bloated, inefficient SUVs with 50s Japanese Sci-Fi styling, and Pick'em up Trucks with pointless, "mine is bigger than yours" six-foot-high front ends..

            impressive, but are they what people want?
            I don’t believe so, but it is what they are sold.

    • That’s why you need a limitless resource that is everywhere and relatively easy to convert and utilize.
      Duh!

  6. I fail to imagine how vapor can be extracted from the turbine exhaust and only the steam being sent to the condensers. But it’s fascinating to see the ideas being developed.

    • That’s the big question which is core of at least two dozend german research projects inside the LuFo calls (“Luftfahrtforschung”) over the last ten years.

      While it has made stationary gas turbines for coal or atomic power plans extremly effictive to really “push water” through the core it’s a whole different thing for an airplane. In an airplane, you need a clossed-loop system because you don’t have a river or lake at hand.

      • The water used is a product of combustion of the fuel in air. Hydrogen from the fuel, oxygen from the air.

        • The issue is, yea it can be done, at what cost and do all the issues make it worth it?

          • and that is what they are trying to figure out. is the improved efficiency worth the complexity.

            I expect the hybrid portion will be a hard sell, but if the steam portion proves light and reliable enough to more than pay the weight and maintenance freight, it will become an expected feature.

          • different domain:
            household heating has gained quite a bit of efficiency from exhaust condensation.
            ( about another 100°C equivalent or over all 7..8% gains in efficiency enabled via lower temp heating circulation. Technology derided to no end back in the 80ties here. 90+% coverage today for NG )

          • I have dealt with Condensing Boilers as well as boilers that have feedback mix of fuel and air for higher efficiency.

            You pay for that efficiency in complexity and needing a Factory tech to tune them correctly and then repair them when they break.

            Flip into if you need max heat you shift to plain heat output to a set temp (Alaska tends to need max heat, its 4 deg F right now and just came up out of -5 F).

            If you don’t want your house to freeze up on a failure when you can’t get any tech let alone one that knows the specific mfg model you have? Well then get two (or 3). We had one building we had 4 in and we had supplemental heat for that building in gas heaters as well. That floor heat is sooooo slowwwww to recover (and mechanics hate is as it needs to be 90 deg to get any heat out of it and their feet sweat like Niagara Falls.

            We had another building that has a problem with cracking cast iron sections (and no one had an answer as to why, all standard remedies failed)

            So I found a thermal shockproof boiler, while the manager wanted a energy efficient replacement. It got thrown up to Memphis for a decision.

            The decision was the one I found. The Head Engineer ruled that it was tried proven and we don’t need the pain of a new whiz bang efficient unit (which as time went on proved to be maint intensive from reports of other mechanics who had to deal with them)

            When you only have two boilers, you want them reliable. Yes I have had two boilers fail and only because they were simple did I skate through on one while I got one fixed.

            One replacement boiler had all the efficient mix stuff and they kept faulting out. Again it was often two though one of the 3 kept going (phew)

            The master tuner could not get them to quit faulting entirely.

            You get a different perspective when you are on the point end of the spear.

        • From where the water from the exhaust will be supplied? The paper said that is extracted from the core exhaust in a condenser, than heated to steam by the vaporizer which will drive a steam turbine that co-drives the fan. Okay , so water will be carried onboard ?

          • Air in the bypass is cool enough to condense water from the core exhaust.
            Water is present in the exhaust as product of the combustion reaction. So some of the core exhaust will be routed to a zone in thermal contact with the bypass. The condensate will have to be separated from the cooled exhaust gas and pumped to a zone in contact with the high T exhaust to be vaporizer, the steam then will enter a turbine linked to the fan spool and finally the depressurized steam will be re-injected as cool gas in the combustor to reduce temperature and reduce NOX formation.

            No storage of water per se as it is generated in situ. However the number of elements is quite high : 2 heat exchangers 1 pump 1 turbine 1 separator 1 injector. And all that needs to be controlled so sensors flaps/valves etc to make sure it does not freeze up that pressure downstream of turbine is higher than in the injector etc. I would not be surprised this is only active during cruise, I doubt it cn be designed with a turndown ratio sufficient to be operable in all phases of the flight cycle.

          • Complexity as seen on any compounded engine design. This will not be easy.

            Question is will this be turned more or less 1:1 into a commercial design as is or will it supply detail solutions only?

            in recent times we’ve mostly seen operationally simple solutions: sophisticated coatings, a gearbox but moving parts complexity of an adjustable nozzle was avoided.

  7. Has something like this been done with ground based gas turbines? I can find water injection but no recycling/steam turbine applications.

    • @Jan
      Good question.
      Water injection system provides augmentation by allowing water to be sprayed into the air inlet and diffuser section of each engine. Water injected in this manner serves to increase the density of inlet and combustion air.
      The result was increased thrust.

      • There are 2 versions of water injection, either in the inlet that also helps to clean the first rows of blades and vanes or water injection into the combustor, either in the fuel nozzles (like JT9D-7AW) or onto the hot structure that will lower combustor temperature and increase mass flow thru the turbines increasing power. I agree that this seems to be the first step in running the GTF on LH2 where you can use its immense cooling capacity inside the engine before letting it exit in the fuel nozzles. Condensing “dirty” steam in the exhaust might force solving lots of performance, cost, mass, filter and reliability problems before moving to hydrogen and a few new problems that the P&W rocket people has been solving since the RL 10.

    • Probably not practical on a ground-based turbine because water is cheap at the surface. Maybe in a desert. The Ukrainians (Mashproyect) had a water recovery system for gas turbines back in the early 2000’s. I think they installed some in Iran.

  8. Absolutely fascinating! Thanks for an outstanding look into the future, Scott.

    > The hybrid part requires a power distribution system in the aircraft and a propulsion battery, Figure 5. Airbus is looking after the integration aspects of these parts of the project.<

    Of course Airbus is involved and forward thinking, and where’s Boeing?
    Oh that’s right their CEO just two weeks ago put the nail in their development coffin and said they’ll “wait for a new technology engine before they make a move”.
    Meanwhile their senior engineers and technical expertise are bailing out in droves.

    Many of the previous commenters are skeptics and I understand this. But someone is using some some very smart physicists and engineering on this concept.

    The jet when originally developed in the 40’s was an exponentially 100 leap in technological development from the radial pistons.

    I think this technology is the next leap.

    • Article is by Bjorn. give credit where credit is due. Bjorn is amazing in the depth of his knowledge

    • The first operational gas turbine that produce horse power was built in Norway in 1903. It was used for about a decade to produce compressed air. Built by a guy named Elling.

  9. Meanwhile, speaking of technological progress, the Air Force is set to unveil Northrop Grumman new B-21:

    https://www.defenseone.com/business/2022/11/revealed-public-finally-gets-see-b-21-stealth-bomber-week/380175/

    Unlike the B-2, Boeing was not involved with any development.

    > Digital engineering has allowed Northrop to build the first B-21 “as close to production-like as possible,” unlike traditional aircraft development projects, where companies made bespoke X-planes that were flight tested and then heavily modified before entering production.

    “By being able to burn down a lot more risk digitally, we’re able to take this step, which cuts years out of the overall development program and really wrings a lot of risk out,” Jones said. “Hopefully we can get started and up and running in production much more efficiently and effectively.”<

    You will never ever see Boeing think this way. Not anymore.

    • “You will never ever see Boeing think this way. Not anymore.”

      But they do talk a lot “in that way” 🙂

      Boeing also seems to go for SAF fuels to go greener.
      ( lowish effort coopting other entities work 🙂

          • Bill7:

            The statement was Boeing was not doing it, not the overall losses of BDS. That statement was wrong.

            And in fact the smallest losses were on the T-7A (I don’t believe MQ-25 had any but could be wrong)

            Currently Boeing is transition into production on the T-7A program.

            NG does not know what they have yet and that program is deeper black than the much more public T-7A.

            NG underbid Boeing (and LM?) on the program. Said bids are a national secret. Cost overruns are a given. Stay tuned.

          • @TW

            Time to read hundreds of articles and able to *remember* all the imp. bits!!

            Calhoun said Boeing’s digital tools are not mature enough!

            Q1:
            – the T-7A Red Hawk program recorded a $367 million charge spread over development and production
            – $78 million charge to the MQ-25

            Q2:
            – the T-7a add another $87 million charge
            – $147 million charge on the Navy’s MQ-25. In 2018 the Navy awarded Boeing an *$890 million* fixed-price contract for the MQ-25

            Q3:
            – $285 million charge for the T-7a
            – $351 million for the MQ-25

            Q1-Q3 total
            T-7: $739 million
            MQ-25: $576 million

            Soon Boeing is responsible to pay more than the Navy for the MQ-25 program

            Numerous Boeing programmes were also cited by the GAO as being behind schedule, including the KC-46A, T-7A, MQ-25 …

            Hundreds of million wrote-off here, hundreds of million wrote-off there …

          • TW: “And in fact the smallest losses were on the T-7A”

            IMU Boeing “coopted” SAAB to create a sane and workable framework for that project?
            B’s job : PR and partial execution?

            ( I once wrote that B should get a license and produce/sell rebadged A320 to get ahead 🙂

            The C5 US automakers did this successfully leveraging designs from Korea.

          • @Pedro

            Well, to be fair – TW is not wrong;

            BA only lost about three quarters of a billion and half a billion on the T-7 & MQ-25, by those numbers. That’s hardly an inconvenience, given what was written off (and what has yet to be written off) on the 777X and 787 programs.

            If I’m a Boeing shareholder, I’m scoring that as a win. You know the c-suite boys are…

          • @Uwe: Who would buy a Boeing made A320? With their production quality or lack of QA, it would be hard to sell. Or they would end up having to halt production and rework their inventory a few times.

          • BA touted about its digital and modernized 737 wing production at Renton.

            The [inconvenient] truth is:
            according to FG, ‘ “The 737 line has also suffered “quality problems”, BCA CEO Stan Deal said on 2 November. A source within Boeing says the company this year repeatedly stopped 737 wing manufacturing to fix production defects, including miss-drilled holes, partly due to errors made by new staff.’

  10. I remember my aircraft design lecture notes from the early 2000s which already had an engine concept with a “Zwischenkühler” (intercooler) shown. That shows the long way such concepts need to go.

  11. “The WET technology is projected to save about 10% of fuel consumption”

    Presumably this is per trip, and not per seat?
    After all, the technology adds 3+5 = 8 tons empty weight in the example given above. Part of this can be compensated by carrying less fuel, but — presumably — the rest will imply reduced passenger/freight payload?

  12. It’s nice when kids play together 😉.

    On a semi-related note; PW used the gear system to improve its offering. CFM used advanced materials (I think). Would there be another leap forward if CFM combined it’s improvements with PWs? I know they wouldn’t actually do it, but wouldn’t that be a good study – if it’s improvements in different parts of the engine – for the benefit of the planet.

    • P&W can add the approach that CFM used (hotter combustion) by upgrading the parts in the engine (and or some mods)

      P&W was cautious on more exotic and higher cost materials and still got a better gain than LEAP.

      GE clearly choose the path of more exotic and costly (Safran following along)

      CFM cannot duplicated GTF in other than an all new engine.

      GE and RR make more sense as a link up for getting a GTF.

      • It should also be noted that while RR and GE are the top entities, P&W has been part of other Corporate Holdings for a long time (United Tech and Raytheon now)

        It would be Raytheon making any decisions on collaboration.

  13. On the subject of new engine tech — previously hinted at, but now formally launched:

    “Green push: Airbus develops first ever fuel cell engine as it launches electric battery partnership”

    “It is the first time the world’s largest planemaker has branched out directly into developing engine technology, but zero-emission project head Glenn Llewellyn said it would not necessarily go it alone if the system ended up being deployed.”

    https://www.cityam.com/green-push-airbus-develops-first-ever-fuel-cell-engine-as-it-launches-electric-battery-partnership/

    https://www.rte.ie/news/business/2022/1130/1339209-airbus-develops-fuel-cell-engine-for-hydrogen-plane/

  14. A CF6 delivers 20% of its thrust from the core. Presumably a heard fan delivers less, but how do you extract water from the core exhaust without slowing it down, resulting in less thrust and less efficiency?

      • that is by air mass, not thrust. not sure what the thrust numbers are, but the air coming out of the core is going a lot faster than the air coming out of the fan, so it produces more than 1/12th of total thrust.

        • “20% Thrust from core”
          Bog standard CF6 comes with 5:1 BPR 🙂

          If the gas generator output has been properly “worked” core exit speeds should not exceed bypass speeds by much. ( optimax: same speed )

          intetresting in context: RR years ago published a graphic showing optimum BPR vs. OPR/core efficiency.

  15. In related P&W GTF news, Croatia Airlines is (a la airBaltic) going to become an all A220 operator, with a firm order for 6 aircraft (-300’s) and lease arrangements in place for an additional 9, bring the fleet to 15.

    https://www.airbus.com/en/newsroom/press-releases/2022-11-croatia-airlines-signs-firm-order-for-six-a220-aircraft

    In a first….Croatian is dropping an order for the A320Neo and switching to the A220. The new aircraft will replace A319’s, A320’s & Dash 8’s that the airline currently operates.

    • Also PW pledged to finally start shipping replacement engines for Go first India and Indigo’s PW powdered AB narowbody fleet …
      Currently 75 grounded due, engine issues and lack of spare parts.!!

      • I heard Ryanair has resorted to supplying Boeing with some of its own spare parts in an effort to speed up delivery of its backlogged Max jet 🤔

        -> Airlines are also operating with lower inventory. With the pandemic-induced collapse in air travel, carriers found different assets to sell to raise cash, including their stores of spare parts, expecting a slower, yearslong recovery
        -> The shortage of parts is leading to an increase in the time it takes to move an aircraft through a heavy maintenance check. For some engine types, overhauls that typically take 60 days can last up to 100 days; on airframes, heavy maintenance checks are now about seven weeks instead of four

        • @ Airdoc
          “When do you think Emirates will bag it and cut their loses?”

          In the not-too-distant future, I imagine.
          Tim Clark is already talking about ordering A350-1000s, in addition to the 50 A350-900s that he has on order.
          Publicly, he keeps repeating that he’d like the 777X, but part of him probably realizes that the plane is — increasingly — a fata morgana.
          BA doesn’t have the money for re-designs, and industry rumors suggest that the 777X may need various modifications…

          • The vagueness from all parties on the 777-X, along with the continued stutter-step delays, really makes one wonder.

          • Or there was an issue with the GE engine that there is not a time issue in resolving and they are taking their time as the schedule is not engine driven its FAA compliance issues.

            And while it impacts Boeing, the engine issue(s) are not created by Boeing in any way shape or form. Boeing has no fingers in that supply chain.

            New engine always have problems. PW, RR and GE (the infamous Turbine shuck on the 787).

            Rather than rant and rave maybe get the facts?

          • @ TW
            Nice fantasy.
            Share it with Tim Clark and see how comforted he’ll be.
            The GE9X has running for 6 years now…bit late to be discovering glitches.

        • Exceptions to all sorts of regulations are made for vintage cars and steam locomotives, so why not for legacy aircraft?

          It’s the *new* aircraft that should have modern systems. Dinosaurs like the MAX should be confined to Jurassic Park if they don’t meet minimal requirements.

        • Ho ho hold!!

          I thought it’d be the stuff for kids – notice any difference between 900ER and MAX 7/10: say certification, one was certified *15 years* ago, the other?? An uncertain future ATM.

    • Airdoc:

      As I recall, the premier battery mfg in the world is SAFT out of France.

      Seems like there is a plethora of battery mfgs and research into all sorts, we need more people with their finger in that pie?

  16. This looks like it could be a great innovation, and perhaps the engine technology that Boeing is looking for to develop a new 737 replacement model.

    So, in looking at the numbers, you have increased the engine mass by 3t, and adding the hybrid component adds another 5t. Add 8t total. I would question the overall fuel savings, if you are increasing the weight of the airframe by that much. And, are BA & AB going to just accept an 8t increase, which would push all of their frame MTOW numbers up? Would airlines accept these weight increases, as it will potentially increase their landing fees at airports around the world? Is the tradeoff in fuel efficiency enough to offset the increase in landing fees?

    • GS:

      That assumes Boeing is even staying in the Commercial Aircraft segment and like the RISE, pie in the sky and a fig leaf excuse to kick a program down the runway while Calhoun escapes with 10s of millions.

      • I think CEO bonusses should be based on long term portfolio health, HRM and competitive position, instead of short term stock value & free cash flow.

        Problem is people who decide over that (supervisory board) are usually in the rewarding scheme too.

        Maybe when US government steps in to save the day, they can enforce change in the executive rewarding packages area. The current ones proved counterproductive & damaging for the company.

        Boeing executives make 3-5x more than their Airbus colleagues. That ain’t right.

        • keesje:

          Execs should get NO stock and they should be paid on how they do their jobs.

          But with the Boards complicit in the old boy network (with the occasional woman allowed in) they all serve on each others boards and its a give them bonus even if the company craters

          • > they should be paid on how they do their jobs.

            There’s the rub. What is their job? Who do they serve? Current investors? Employees? The public? Some combination?

            US theory leans towards serving current investors, the future be dammed.

          • There is a risk of “Pump and dump” stocks by the present board of directors instead of a balanced view of keeping paying customers, employees, owners and suppliers equally happy for the long run as you develop new models that have better performance, are lighter and cheaper to build on a regular schedule. Most car manufacturers do it every 3-6 years. See Mercedes CEO comment, “Our goal is technological leadership in the automotive luxury segment and in the area of premium vans while remaining committed to our ambitious margin targets. Mercedes-Benz has what it takes: a clear strategy, a highly qualified and motivated team, as well as strong support from the entire supervisory board. With the most desirable cars we want to grow profitably and create sustainable value for our customers, employees, shareholders and partners.”

          • Jbeeko

            Self serving philosophy does not make it a theory.

            A Corporation was intended to serve the company (including employees) and investors. So there is nothing about who, it was understood and that is why it was structured the way it is.

            Its been corrupted and the fig leaf nonsense about a question of who and why the management serves is no more than that (and I am being terribly polite but cow piles are cleaner)

            Pillaging the company is a modern thing, once you kill the company its gone and there is no theory to that.

            You know things are rotting at the core when Calhoun gets a bonus for doing his job. By that standard he should get another one for fixing the 787.

            So yea, the theory is nothing more than a steaming pile of manure

          • “When Immelt took over from Welch, he addressed a gathering of top G.E. managers in Boca Raton. “Only time will tell if Jack is the best business leader ever, but I know he is one of the greatest human beings I have ever met,” Immelt said. But by that point the Welch legend was so huge that such blandishments seemed obligatory.

            What Immelt quickly discovered was that Welch had handed him a mess: a company built out of pieces that had no logical connection. Once the global financial crisis arrived, the elaborate game that Welch had been playing with G.E. Capital collapsed. Wall Street woke up to the fact that a non-bank was every bit as risky as a real bank, and the company never quite recovered. Immelt was eventually forced out, in disgrace. Almost two decades after Welch handed the reins to Immelt, Cohan met Welch for lunch at the Nantucket Golf Club. All Welch wanted to talk about was how terrible a job he thought his successor had done. The share price had collapsed, and Welch was disconsolate.”

  17. The program is a way to get research dollars to the European companies and by extension PW and GE with their European partners in MTU and Safran.

  18. Reuters
    U.S. senator presses FAA for details on Boeing 737 MAX alerting system

    -> In a previously unreported Nov. 23 letter to the FAA seen by Reuters, Cantwell sought additional information on its certification of the Boeing 737 MAX fleet and compliance with the crew alerting requirements” by Dec. 5.

    -> Cantwell’s letter asked “to the extent FAA has identified safety deficiencies with 737 MAX’s flight crew alerting system, please describe FAA’s plans to immediately address these safety concerns.”

  19. We’ll, I’m sceptical. Condensing steam from exhaust will inevitably decrease the pressure drop across the LPT and reduce both thrust and efficiency. Then there’s the weight. The extracted water, which must not freeze or re-evaporate then has to be heated to high pressure steam to be put through a turbine somehow co-coupled with the fan. Where does the heat come from without decreasing the thermal efficiency? After it comes out of the turbine it somehow has enough pressure to flow into the combuster , near compressor discharge pressure and presumably temperature. To make a significant difference to the fan torque it’ll have to be very, very hot. Also stoichiometry suggests mass flow of steam cannot exceed fuel flow, which is small compared to airflow.

    • I think they need to condense the steam to water, then have a boost pump to raise pressure to burner pressure and finally heat it with exhaust air to make high pressure steam to drive a steam turbine and still have exit pressure to inject it into the burner. It smells rocket parts costs and very hard to produce fault free in volumes. Maybe they use Reaction Engines heat exchangers to quickly progress.

  20. The subject of superconductivity in power distribution systems was touched upon by Bjorn in his recent hydrogen fuel cell series. Airbus is now taking steps in that direction, via a partnership with CERN:

    “CERN and Airbus partnership on future clean aviation”

    “Today, CERN and Airbus UpNext, a wholly owned subsidiary of Airbus, have launched an innovative collaboration to explore the potential use of superconducting technologies developed by CERN for particle accelerators in the electrical distribution systems of future hydrogen-powered aircraft.

    “Superconducting technologies could drastically reduce the weight of next-generation aircraft and increase their efficiency.

    “The partnership focuses on the development of a demonstrator known as SCALE (Super-Conductors for Aviation with Low Emissions), bringing together CERN’s expertise in superconducting technologies with Airbus UpNext’s capabilities in innovative aircraft design and manufacturing.””

    https://home.cern/news/news/knowledge-sharing/cern-and-airbus-partnership-future-clean-aviation

  21. Reading this I’m reminded of the Wright turbo-compound engines from the late 50s. I know about the only things these concepts have in common is a) they’re both aero engines, and b) attempt to recapture power, but if development is successful I hope it’s much more reliable than that old Wright engines!

    • I was thinking the same thing.

      I have seen those engines, you have to dismantle major portions just to get to the wear parts. No wonder they failed so often. Desperation to keep them viable in an age when they simply had not future.

      Turbo compounding has been tried in bit trucks as well and it just does not pay.

    • Serial production and one a month if that. Not exactly mass. And certified by a fully Captured Regulator that so many rail against. Ungh.

      • Indeed.
        The big irony is that the referenced chip ban will have minimal to zero effect on China’s chip plans. Mhh…where have we seen that before? 🤔

      • From DP’s link (thanks):

        “..On top of that, the worsening of Sino-American relations along with the decision of China to grant Airbus SE (OTCPK:EADSY) a major contract to deliver over 300 planes to its state-run airliners in the following years indicate that Boeing is about to lose a dominant share in one of the biggest aviation markets in the world due to geopolitics. What’s worse is that it appears that Boeing still hasn’t remarketed any of its planes that are designated to its Chinese clients to customers from other countries, as the hopes of reentering the Chinese market are waning with each year. As a result, we could safely assume that Boeing would continue to struggle to reinvent itself, since the grounding of the 737 MAX due to safety issues in the past continues to haunt the business to this day..”

  22. Here’s some early Christmas cheer 😏

    “Top Reasons Your Next Job Should Be at Boeing”

    https://news.clearancejobs.com/?p=1128550

    Particularly striking:
    “People feel valued when they’re listened to, and Boeing’s leadership values and rewards innovation and ideas from employees throughout the company. “From myself, all the way up to David Calhoun (the President of Boeing), we like to hear what your thoughts are on strategy and what is good for the business,” said Roxanne.”

    Who’d have known? 😎

  23. “The GE9X has running for 6 years now…bit late to be discovering glitches.” (!)

    Something bigger is going on, I think.

    • Well it is big (engine)

      And I think RR was in service for 4-5 years before the Trent 1000 came crashing down on their heads.

      On wing the time on any given engine is minimal.

      Good question is do they have one running in a test cell? Or did they meet the minimum and the rest is intended to be on wing?

      P&W also had a number of issues after the GTF went into service. One fix acualy was worse than the first one (seal).

      Until Boeing gets FAA approval to start the official flight tests the time spent is small questions that have come up to check out. They were not putting any serious flight time in as it has to be done again.

      So with the delays, they likely are taking their time and have the time (a bad thing to be in that position but they can take advantage of it in this case)

      Why spiral off on no information?

  24. Airbus delivered 66 commercial aircraft in November, bringing its tally so far for 2022 to 563.

    “Airbus will announce November deliveries on Dec. 8, which is also seen as the opportunity to announce any update to end-year goals. Two sources said this had not been ruled out, while noting Airbus has a pattern of positive surprises at end-year.”

    https://www.nasdaq.com/articles/airbus-delivered-estimated-563-jets-jan-nov-sources-say

    As of this morning (CET), Airbus had already delivered 13 commercial aircraft in December.

    • The Airbus surprises always were orders that they cooked the book for to beat out Boeing.

      They can quit cooking the books now.

      Was the production not to be 700 something? Off to kind of a slow start in December for that.

      • 13 deliveries in one day is a “slow start”…?

        Further: explain how Airbus “cooks the books” with physical deliveries…

        • Airbus has *already* delivered more aircraft in 2022 than that one commenter said they would for the year total, and they still have almost a month to go.

          We’ll see how it goes just after the New Year- especially in comparison w/ the other guys.

        • According to those who insisted to “count” deliveries?? May be twelve is “two” much for those who learned counting by fingers!

        • @Bryce…Looks like your AB delivery predictions will fall far short your exaggerated expectations…
          Likely to miss that target of 700.
          .by a margin of 70 !!!
          So much for all your hype.!!!

          • Airbus itself says the year-end figure will “not be materially less than 700”.
            Shall we wait and see what the figure is on Dec. 31?
            This morning, the count was at 23 (in 6 days).

            “So much for all your hype.!!!”

            p.s. Constant agitation can form a significant health risk…

      • “that Airbus cooked the book for to beat out Boeing.”

        you can’t wrap your mind around it can you?

        cooking the books ( like Boeing does with moving payments from customers left while moving subcontractor liabilities to the right in time) gives you _once only_ good numbers.

        Doing it every year can’t be done via cooking the books.
        So please stop posting such tripe.

  25. We already knew this from the EASA MAX RTS AD from 2 years ago, but Dominic Gates is now spelling it out for the doubters:

    “If Congress doesn’t mandate Boeing 737 MAX safety retrofits, Europe will”

    “Even if Congress doesn’t force U.S. airlines to retrofit two new safety upgrades in their Boeing 737 MAX fleets, Europe’s aviation regulator intends to ensure those enhancements are mandated for carriers there.”

    “EASA’s head of communications Janet Northcote said via email Friday that “Boeing has committed to make these upgrades available for retrofit.”

    ““The actual retrofit of the in-service fleet can be achieved by different means, including possibly mandatory action from the FAA or EASA,” Northcote added.”

    “To get the MAX back in service in Europe, Boeing agreed with EASA to develop two major safety upgrades for the MAX 10 — the final and largest MAX variant — that within a few years afterward would be retrofitted to the in-service fleet of MAX 8 and MAX 9 airplanes.”

    “The first upgrade is a third measure of the jet’s angle of attack — the angle between the wing and the oncoming air stream — a key data point that feeds into various flight control systems.”

    “The second retrofit requirement is for a switch that would enable the pilot to silence an erroneous “stick shaker” — a stall warning that vigorously vibrates the pilot’s control column.”

    “When faced with the prospect of more stringent safety rules applying to European airlines than to U.S. carriers, either Congress or the FAA might be embarrassed into mandating the retrofits.”

    https://www.seattletimes.com/business/boeing-aerospace/if-congress-doesnt-mandate-boeing-737-max-safety-retrofits-europe-will/

    • “..A source familiar with Boeing’s position, who spoke on condition of anonymity because of the sensitivity of the ongoing negotiations in Congress, said the company has agreed to offer these retrofit enhancements as an option.

      “We’ll make it available to our airline customers,” the person said. “If they want them retrofitted on the rest of their fleet, absolutely.”

      >>Cantwell’s amendment would make that mandatory. <<
      It would require the FAA to take enforcement action against any U.S. airline that doesn’t incorporate the retrofits.."

      So generous! of Boeing to oprionally "offer" to airlines what should already have been there long ago..

      https://www.seattletimes.com/business/boeing-aerospace/cantwell-pushes-to-clear-boeings-final-737-max-models-with-conditions/

    • Looks like Christmas may be coming a little early this year for Boeing..
      A nice gift wrapped 787 order, leaving Airbus with nothing more than a lump of coal for their stockings !!! 🧦
      Seems to be a developing trend lately on the 350 front…
      Losing substantial orders, a growing fleet of parked aircraft,SAS being the latest…
      Don’t fret AB
      You know Air India just waiting for that mega discounted order looming !!!

        • Not only that: somebody didn’t ask himself what kind of discount BA was forced to give on any *potential* 787 order, so as to win from the competing aircraft. I suspect VERY thin margins, à la the recent Southwest and Delta 737 MAX orders.
          No point in bagging a big order if it doesn’t help dig you out of your debt pit 😉

          • Does fleet commonality and fuel efficiency mean anything to you Sir Bryce…
            Kinda of a no brainer ,not to introduce a new type to your widebody fleet..
            Guess when that’s all you have to fall back on is huge discounts ..
            Can see your frustrations of losing that huge United 350 order..

          • @ TC
            When both AB and a carrier know that an order is probably going to BA (e.g because of fleet structure), they play a win-win game that screws BA 😏
            How? AB keeps lowering price (knowing that it won’t win anyway), and the carrier then runs to BA and demands that the AB price be matched, in a cycle of iterations. BA takes the bait, and ends up with an order that’s good for PR but bad for the balance sheet 🤕

            That’s how it went down with the KC-46A and the SW 737-7 order. AB laughs in the background while BA sinks further into its financial marsh.

            Welcome to the real world 😎

        • 787: the Wednesday ahead of the NTSB battery report ( after stockmarket close on a Saturday )
          a rumour was floated by some busybody journo that a German Airline would order another 20 787.
          Though rather damning the report did not “touch” the share price on Monday at all.
          Rumor was false, airline had reduced, morphed to -9 an existing order. Finally canceled.

          What important “high impact” media event is coming up for Boeing?

          • Good background, and a well-posed question. I love a good question..

            here’s one more: what’s propping up Boeing’s current stock valuation of $180+ ?

      • I think some people are looking at A350-1000 economics across the Pacific for UA. 350 Seats & a lot of cargo. And what efficient,
        low risk alternatives there are / aren’t..

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