Pontifications: Engines, engines, engines

By Scott Hamilton

Oct. 29, 2018, © Leeham Co.: Engines, engines, engines.

News emerged last week that Rolls-Royce admitted its continuing problems with the Trent 1000 that powers the Boeing 787 now bled over to the Trent 7000.

RR will fall short of delivering the number of engines need to Airbus for the A330neo, meaning fewer deliveries of the airplane this year.

Boeing said it is clearing its inventory of 737 MAXes, but CFM LEAP engines are still late, slowing the effort.

Pratt & Whitney’s GTF engine deliveries to Airbus are caught up, but technical issues still plague in-service engines. CFM still has technical issues as well, though not as severe or persistent as with GTF, with its LEAP engines.

Engines for the NMA

While eyes continue to focus on Boeing’s business case challenges for the New Midmarket Aircraft, the focus on engines has largely been overlooked.

LNC pointed this out as long ago as last March. See here and here. In May, a leading industry official said engines remain a “huge” issue for the NMA.

Steve Udvar-Hazy, non-executive chairman of Air Lease Corp., doesn’t think the engines will be ready in time for a 2025 entry-into-service (he predicts 2026-2027). This is because of all the problems they are dealing with, as outlined above.

Hazy is one of the most-clued in industry executives you can find.

Engine OEMs are due to submit their proposals to Boeing for the NMA by the end of the year. Airlines would like two engine choices and there is a contingent within Boeing that would, too.

But because the engine makers don’t subscribe to Boeing’s market demand forecast of 4,000-5,000 Middle of the Market sector airplanes (including Airbus) over 20 years, two of the three want sole-source selection, LNC is told.

The engine OEMs see a market of about half that of Boeing.

Splitting the market

With Airbus assumed to account for half the MOM sector, the business case for the airplane depends in large part on whether Boeing’s forecast or everyone else’s is correct. The engine makers then split the Boeing share of the MOM sector and even with the aftermarket MRO business model used by engine makers for decades, these OEMs remain skeptical.

Boeing also wants a share of the engine OEM after-market largess, LNC is told—because that’s where the money is. Needless to say, the engine OEMs are less than thrilled at this desire.


59 Comments on “Pontifications: Engines, engines, engines

  1. So it could be could if Airbus needs an 45k lbs engine too. That could stimulate the OE’s.

    It seems 42-45k lbs developments of the GTF & LEAP would be enough for an A322/323 XLR, but I wonder if it would do for a twin aisle NMA.


    Udvar says an entirely new engine is a big riksk and might take a lot of time. Specially if Airbus moves ahead anyway.

    • Hi Keesje, what is the MTO thrust of the PW for the 321’s, most information claim 33Klb, others suggest an 35Klb is already available.

      That apart, AB’s big challenge will be the wing for an A321X. How much will it cost and how long will it take? For longer range versions the cruise speed will have to be improved. An “A321+XLR” with 12 more seats and effective range of around 4500Nm will be competitive but an MTOW of 102-105T will be required?

      On speed, saw on Flightaware yesterday an SIA 359 doing 706 mph at one stage between Houston and Manchester.

  2. Well, I was pointing out since the first news about the NMA surfaced that there’s no engine, but nobody was listening. 🙂

    But seriously: As we can see with the Trent 1000 debacle: When you try to rush a highly advanced engine into service you may end up with a terrible situation for both the plane maker and the engine supplier. Now, for the NMA Boeing certainly desires an engine that features all the latest advancements, especially as we are experiencing a steady increase in oil prices. Such an engine simply doesn’t exist in the desired thrust range, so it’ll be a completely new development with both a new core and a new fan, probably also a new gearbox for the fan. This should take 8-10 years from the definition of specs to entry into service. This brings us easily to 2028-2029.

    The alternative would be an engine bases on existing designs. That might take 2-3 years out of the schedule, but as there is also the issue of a not-existent production system for the ovoid CFRP fuselage, which will also take several years to develop and test I don’t see the urgency.

    • It seems to me Boeing might have change it’s approach towards Pratt. They are progressing with their next-generation Geared Turbofan (GTF) engine propulsor technology program. testing, validating, adjusting. Boeing loves UTC anyway, so..

    • The first run of the PW1100G was in 2008, 10 years later things look as if it’s improving but not sorted out yet. GE launched the GE9X derivative in 2012, EIS 2020, that’s 8 years.

      So EIS of a new engine somewhere between 2028-2030 if you optimistic. With Boeing aiming at 2025 it must be a derivative of the CFM, not a big step forward but most likely a “cheap” and safe way forward.

      • Keejse: UTC being the gear company that lost on the 777 and the one that said hey were cautious on bidding Boeing work due to the slashes in return expected?

        • Hi TW, it’s the UTC that is Pratt, BE/A, Rockwell Collins, UTAS, Goodrich all in one. A 50 Bill company that says “no” to Boeing if they don’t like a business case. And that’s not the desired response to Boeing partnerships for success. A background fight for the NMA business case, now they have the most promising engine technology.

    • Hello Gundolf,

      Regarding: “Boeing certainly desires an engine that features all the latest advancements,”

      According to the following excerpts from the 6-27-18 CNBC article at the link below, which cites Jon Ostrower’s “The Air Current” as a source, and also several other articles that I have seen, Boeing is asking engine manufacturers for a 45,000 pound thrust engine with 25% better fuel efficiency than the engines used on 757’s. The 757 first flew in 1982, thus Boeing is seeking a 25% specific fuel consumption improvement over the 40 year old 36,600 to 43,500 pound thrust engine designs that were used on 757’s, not a 25% specific fuel consumption improvement over the current state of the art engine designs used on A320 neo’s and 737 MAX’s. In other words, Boeing wants a 45,000 pound thrust engine with more or less the same specific fuel consumption and technology as an A32o neo or 737 MAX engine, and not a 45,000 pound thrust engine that leap frogs the technology used on A320 neo and 737 MAX engines. Those contemplating engine moonshots need not apply. My understanding is that initial RFP’s were due in June, and that the December deadline is for for final best offers.

      My understanding of Bjorn’s Fehrm’s series of paywall articles assessing the efficiency of Boeing’s proposed NMA over the last several years, is that whatever engine technology one uses, old, current, or next generation, a single aisle design and NMA twin aisle design using an elliptical CFRP fuselage, will have similar fuel efficiency at around the size of the proposed 797-6 if both designs use the same generation engines and have the same design range, and that at the size of the proposed 797-7, the NMA style design would have better fuel efficiency than a single aisle design using the same engines and having the same design range.

      “According to the aviation magazine “The Air Current,” Boeing has given the manufacturers a Request for Proposals (RFP) deadline of June 27 to submit plans for a new engine that burns 25 percent less fuel than turbines used on Boeing’s 757 planes.”

      “Morris said Pratt & Whitney’s proposal could also be in the mix if it can demonstrate that its GTF technology could scale up to the 45,000 pounds of thrust that Boeing is said to be demanding.”


      • In my post above, when I referred to designs of the same size and design range, I should have said, more precisely, designs of the same passenger capacity and design range.

        • The RB211-535 was quite a good engine for its time. Let’s take a look at the cruise TSFC (lb/lbf/h), which can give us a hint of their true efficiency:

          RB211: 0.570
          GE90: 0.545
          RR Trent 500: 0.542
          Trent XWB: 0.478
          CFM Leap: 0.420

          So if these numbers here are correct, it looks like the latest generation (Leap, GTF) could indeed just match the 25% target. The Trent 500 would not, by the way. The only problem is that if you just increase thrust in the same size of an engine, the efficiency is compromised. Thus we would need lager engines with larger core and fan, effectively an entirely new engine.

      • Thanks AP, see the NMA-6X 228 seats (5000Nm) and -7X 267 seats with 4200Nm range. Often wondered if the sweat-spot is not somewhere in between, ~250 seats with 5000Nm range. From a BA perspective this will compete with the 788 to some extent.

        The article comment about an possible AB response, maybe it could be an aircraft along above lines, 5000-5500Nm range, “narrow” 2-4-2 fuselage but still reasonable cargo capacity. PW and RR could potentially JV on an engine of around 50-55Klb thrust to EIS 2028-2030 or so? Guess both learned lessons from the T1000 and PW1100G.

      • So you believe that an aircraft that is significantly heavier, with more cross sectional area and skin wetted area and that has engines that produce 30% more thrust but have similar specific fuel consumption would have “better fuel efficiency than a single aisle design”. Good luck with the maths on that. Some of our Brexit unicorns will need to fly across the Atlantic before that will happen.

        • Chris, please put conventional wisdom aside. You have to be open to change, this is about enterprise costs, game changing technology & exceptionalism. It’s a whole new way of thinking, move on or be left behind. Alternatively we need your solid proof / sources showing this is not the case 😉

          • You can’t just drop conventional wisdom!

            A fuselage cross section that has two aisles and seven seats abreast is going to be wider than one that has one aisle and six seats abreast. Controversial? That NMA cross section is going to have a greater cross-sectional area than the narrowbody. About 66% more area, even if you apply a (not very eccentric) ellipse (which could be done on a narrowbody in any case, nullifying the comparison).
            Even though a narrowbody will be longer, the difference is in wetted area between that fuselage and the NMA will still be favourable.
            Net result – the NMA will be more costly and have more weight and more drag and that’s why Boeing are looking for bigger engines.
            If the sfc is the same as current engines, and the NMA engine is producing more thrust then it must – by definition – use more fuel.
            If a narrowbody and an NMA have the same pax load over the same range then it will not be more economical to fly the NMA.
            Using rough calculations, I reckon the NMA engines would need to have about 80% of the sfc as the best of today’s narrowbodies, all else being equal (flight speed, altitude, lift/drag ratio) in order to be competitive. That engine technology isn’t there.
            Plugging representative numbers into the Breguet range equation backs that view up.
            If I put conventional wisdom aside, I have only one resort – faith. Faith in what? Its up to you to tell me what the game changing technology (that can’t be applied to a competing narrowbody) might be. Split tail?
            The only way I see the NMA being competitive is in its stretched version, and then it is competing with 787-8 and A330-NEO aircraft on routes up to 4500 Nm.

        • Hello Chris Lee,

          Regarding: “Good lucks with the maths on that” and the subject of the wetted fuselage area of an A321 or 757 like single aisle aircraft, vs. that of a NMA like twin aisle aircraft, see below for a correct approximate mathematical analysis, along the lines of that Bjorn Fehrm uses in his paywall articles, but much simplified.

          The drag and weight of a three dimensional object depend on its length, width and height, not just on its width and height (i.e. cross sectional area). For a three dimensional streamlined shell structure with a predominately air filled interior, weight and drag will be increasing functions of the surface area of the shell structure. More surface area means more drag and more weight. To match the drag and weight per passenger of two different passenger aircraft fuselage designs, one should thus match the fuselage surface area per passenger, which for a given seating pitch is proportional to fuselage perimeter length per passenger* . For a NMA, the parameter that must be matched to achieve weight and drag that is comparable to an A321 or A321X is thus not cross sectional area, but rather perimeter per passenger. Since a 7 abreast aircraft has 7/6 = 1.17 or 17 percent more passengers per row than a 6 abreast aircraft, a 7 abreast aircraft that has 17 percent greater perimeter than a 6 abreast aircraft can be expected to have similar weight and drag per passenger, as long as neither aircraft is greatly stubbier or more slender than optimal for streamlining, structural stiffness, and tail surface effectiveness.

          If it was not the case that drag and weight depend on length as well as on width and height, then 747’s and A380’s would be really, really long with only 4 or 6 passengers abreast.

          See the free bullet points below from Bjorn Fehrm’s 4-6-17 post titled : “Could an NMA be made good enough , Part 3?”, for Mr. Ferhrm’s conclusions from his more detailed application of the above basic principles to the particular case of the type of fuselage Boeing is proposing to use for their NMA.


          It’s possible to design a dual aisle fuselage with the same perimeter per seat abreast as a single aisle fuselage.

          This will make the central, cylindrical, section have competitive weight and drag characteristics.

          The larger diameter of the dual aisle fuselage will increase the size of the tapered front and rear sections however.

          It’s still possible for an NMA fuselage to be as weight-efficient as a single aisle fuselage, measured per transported passenger.”


          *Here is a concrete example for anyone having trouble following this argument.

          Aicraft #1 has fuselage perimeter P and fuselage length L.
          Airraft #2 has perimeter 1.2P, length L/1.2, and carries 1.2 times more passengers per row as aircraft #1, and has the same seat pitch. Aircraft #2 will thus be able to accommodate the same number of passengers as aircraft #1. It is shorter than aircraft #1 by a factor of 1.2; however, this is exactly compensated for by its carrying 1.2 more passengers per unit length than aircraft #1.

          How do the fuselage surface areas per passenger of aircraft #1 and #2 compare?

          Surface area = perimeter x length.
          For aircraft #1: Surface area = P x L.
          For aircraft #2: Surface area = 1.2P x (L/1.2) = P x L.

          Since the two aircraft have the same surface area, and carry the same number of passengers, they both have the same surface area per passenger.

          • For those who are not theoretical mathematicians or physicists, below are some concrete examples of the correct parameter for comparing, at an approximate level, the weight and drag efficiency of different fuselage designs, i.e. perimeter per passenger, calculated for each of the four fuselage designs that Bjorn Fehrm included in an illustration in the free summary of his 3-18-15 paywall article: “Redefining the 757 replacement: Requirement for the 225/5000 Sector, Part 6”, and also for a Boeing 767.

            Listed from lowest value (highest efficiency) to highest value (worst efficiency). Efficiency will also be subject to the fuselage not becoming to stubby or too slender for near optimal streamlining, structural stiffness, and control surface effectiveness.

            MOM7-200: 194 x 176 inch ellipse, 7 abreast.
            Perimeter = 581.5 inches.
            Perimeter per Passenger = 83.1 inches.

            A321LR: 163 x 155.5 inches near circular, 6 abreast.
            Perimeter = 500.3 inches.
            Perimeter per Passenger = 83.4 inches.

            NSA6-200: 163.4 inch circle, 6 abreast.
            Perimeter = 513.3 inches.
            Perimeter per Passenger = 85.5 inches.

            NLT7-200: 194 inch circle, 7 abreast.
            Perimeter = 609.5 inches
            Perimeter per Passenger = 87.1 inches

            Boeing 767: 198 x 213 inch near-circle, 7 abreast.
            Perimeter = 645.6 inches.
            Perimeter per Passenger = 92.2 inches.

            Significant points:

            I) The perimeter per passenger of the MOM7-200 and A321LR are within o.4%.

            II) The perimeter per passenger of the 767 is 11.1 % greater than that of the MOM7-200 and A321LR.

            I calculated the perimeter of circles and near circles according to Pi x diameter, for the elliptical MOM7-200 I assumed that the cross section was close enough to a true ellipse for the ellipse perimeter calculation tool at the link below to give an acceptable answer.


          • Thanks for chiming in with the math, AP_Robert. I’ve been tempted to write something like that whenever someone claims that a 7-abreast twin aisle can’t compete with a 6-abreast single. That might be true if seat and aisle width are the same, but a tight 7 could match a spacious (fat) 6 like the A320, even if you don’t do a oval fuselage. Seven 17.5″ seats, 1.5″ armrests, and two 17″ aisles = 171.5″ cabin width, which wouldn’t have a problem fitting into a circular fuselage that matches the A320 ratio (185″-186″). If the sidewalls are scraped enough, you could probably increase the seat width to 18″ or the aisle width to 19″ (but not both).

            Also, the A220/CSeries has a terrible perimeter per passenger metric (better than only the 767 in your list), but it still outperforms the 737-7 and A319, so a shortcoming there may be overcome.

          • Hello Cascadian,

            Regarding: “Also, the A220/CSeries has a terrible perimeter per passenger metric (better than only the 767 in your list), but it still outperforms the 737-7 and A319…”

            In addition to being much older designs than the A220, the 737-7 and A319 both run into trouble with my qualification: “as long as neither aircraft is greatly stubbier or more slender than optimal for streamlining, structural stiffness, and tail surface effectiveness.” Both the 737-7 and A319 are shorter and stubbier than optimal for streamlining and tail effectiveness. For a particular number of seats abreast, there is a range of passenger capacities for which that number of seats abreast is optimal or near optimal. As a fuselage design gets stubbier it will at some point be less optimal than a more slender fuselage with one fewer seats abreast, and as fuselage design gets more and more slender, it will at some point be less optimal than a stubbier fuselage with one more seat abreast. For this reason, we see 76 seat regional jets with 4 rather than 9 abreast seating, and 400 seat airliners with 9 (or 10) rather than 4 abreast seating. The smallest proposed NMA model has a passenger capacity for which either 6 abreast seating, or 7 abreast seating with Boeing’s proposed oval cross section, can work reasonably well.

          • Another issue with the 737-7 and A319 vs. the A220, is that both are shrinks of a larger design that was optimized for higher passenger capacities and thus higher weights. One can lighten a shrink some by shortening the fuselage, and using some thinner skins and lighter frames, but without an expensive complete redesign, a shrink will still generally have a weight penalty compared to a design whose original optimization was for the passenger capacity of the shrink. This is also why A330 shrinks with reduced fuel capacity and range are not likely to work well for competing with Boeing’s proposed NMA.

          • Thanks AP, this illustrates the 7 abreast can be competitive. End of the day engines and wing could be key factors. Just hope BA doesn’t make the seats and aisles to narrow just to compete with the 321’s.

            If memory serve me correct Bjorn had an article with pivot points for different cabin widths. Think going from SA to 7 abreast was around 220 seats and from 7 abreast to 8 abreast 260 seats. Interesting the the NMA-6x is 228 seats and the -7X 267 seats, thus BA exploiting the lower and upper limits of 7 abreast.

          • But going from 6 abreast to 7 abreast, involves not just adding one seat but also one aisle.

            The fuselage will therefore be approx. 30% wider but would admit only 16% more passengers. This leads to a 30% increase in fuselage perimeter, about a 30% increase in fuselage weight (and cost) and a 66% increase in cross sectional area. That aircraft will need more thrust and that is why Boeing are asking for an engine that is much more powerful than exists on 757/A321. The rest of the aircraft (stabilizers, wings, gear) would also need to bigger accordingly.

            Absent an improvement in sfc, that aircraft will use more fuel for the same number of passengers.

            I maintain my assertion that a NMA that carries the same number of passengers as a narrowbody , cannot be competitive with that narrowbody. A small NMA is at its least structurally efficient configuration, whereas a large narrowbody is at its most efficient.

            Your 747 analogy is misleading, there are other factors that limit narrowbody capacity and I’m not saying you could build a 260 seat narrowbody. I’d estimate such an aircraft to less than 250 all economy, 226 two-class.

            So I find that I’m still being asked to ditch conventional wisdom on the grounds that the NMA is a new deal, but I don’t see the deal breaker, and I’m comfortable with my doubts.

            Aside from that, history is littered with fantastic technical aircraft that nonetheless became commercial failures (Republic XF 12 Rainbow, Convair CV 990, Trident, Concorde). The fact that Boeing’s business case for the NMA depends upon being able to eat the engine manufacturer’s lunch on maintenance indicates to me that the commercial justification is more impressively negative than the technical one. If I were an engine maker, I’d see a great deal of risk in making an engine that might not sell many units and that would not necessarily generate maintenance revenue. If I were the owner of an airline, I’d rather operate a narrowbody than a widebody if I possibly could.

          • Good points AP_Robert, although the A320 is not much less stubby than the 737-7 (slenderness ratios of 9.29 and 9.16, respectively, compared to 10.18 for the 737-8). In another universe where Boeing had actually bought and competed the CSeries strongly against the A320 family, it would’ve been interesting to see what happened.

          • “For a three dimensional streamlined shell structure with a predominately air filled interior, weight and drag will be increasing functions of the surface area of the shell structure.”

            Sorry that is not correct. Fuselage drag depends on the wetted area (~ perimeter per seat) AND the frontal area among other things. The drag of a commercial airplane in cruise is about 35 % friction (directly proportional to the wetted area), about 40% induced drag (directly related to weight), and 25% pressure drag (form drag, wave drag, excrescences and interference, most of which comes from the fuselage). The pressure drag component is what gets effected by the frontal area in a non-proportional way. A fuselage must punch a hole in the air as it travels, and to do so, it needs to push air out of its way. Generally speaking the smaller its frontal area, the less air it needs to push aside, and the lower its form drag would be.
            As you increase the diameter of the fuselage, the perimeter increases proportional to the radius and area proportional to radius squared: increasing the radius by 30% makes the perimeter per seat increase 30%, but frontal area of the fuselage increases by a whooping 85%. So the frontal area increase can very quickly overwhelm, even if you use a highly elliptical section.
            Also, a fuselage drag doesn’t improve by making it shorter indefinitely. Bellow a critical fuselage length over diameter ratio, the drag will start increasing (aft body effects dominate even with best streamlining), regardless of the reduced wetted area as the fuselage gets shorter.

            This is why a twin-aisle fuselage can’t really compete aerodynamically with a single-aisle aircraft of similar passenger count: to make it work economically, you need to increase the number of passengers to reduce frontal area per passenger to the point that you basically get the size of the existing twin aisle airplanes. You may be able to make up for some of that by incorporating a better wing or using a better engine, but those same things would benefit a single aisle design as well.

            In summary: A reliable comparison of a single vs. twin aisle needs to look at more than metrics like perimeter per passenger or other over simplified metrics.

            All things considered Chris Lee has a more solid argument.

  3. I have been reading all the postings on the Boeing NMA sized aircraft and the statement that say there is currently modern no engine available for it or the Airbus equivalent. I think there is one engine available but it would need some upgrading. It is the Rolls Royce Trent 500 (specifically 553). These engines with Advance core upgrades would suffice for the NMA sized twin-aisle aircraft. Am I wrong on this supposition?

    • Arent they a bit oversized at 60K lbs thrust derated to 53K. When the numbers being talked about are 45K ?

  4. Oh no, we’re in big trouble, what can we do?Sack the engineers, reduce investment and carry on paying big dividends. This is one of the many downsides of capitalism.

    • Another report said a technical issue was reported the night before, but was resolved. Might not be related…

  5. Knowing I’m going to be blasted for saying it, I think the NMA is a dud and it won’t happen. The writing is on the wall and its been there for a while. Nobody can make the numbers work and BA wants the ‘down the road’ revenues from MRO which doesn’t just encroach on the airline in-house MRO, it will also affect the engine makers and third party providers. The market is simply not big enough for everyone to make money on this aircraft.

    • Well said.

      Not only no engine but a development of the A321 would take a large bite out of the lower portion of the NMA niche before the NMA ever flies, at relatively little risk, and with good vibes from LCCs and other airlines who wouldn’t have to retrain pilots, engineers or purchase new inventory at vast expense, and would get their product years sooner than they could an NMA.

      No blast from me.

      • DHR: We tend to disagree here not blast.

        NMA could be a dead end. Boeing does not seem to think so, we get to see next year the start and the hints of where it might go or not go.

        I think the idea has merrit, but execution on a technical level to achieve that merit is a tough nut.

  6. Being a mechanic/technician I have been saying for some time there was a high chance that the issues on Trend 1000 extended not only to the TEN but also the rest.

    Ironic it may be dogged by a single engine choice.

    I believe P&W is best positioned to be an offering on the NMA.

    They were asked by someone (likely Airbus) to offer up a wide body engine a few years back. Add in the experience gained hands on (which means a lot) to the GTF ops they have going and I think they could do it in the time span. GE iffy and RR , ergh.

    As for Hazy, the man has had an amazing career but he has lost his cache. His prediction of 1000 A330NEO looks to be 40 years away. That is rate 2..08 a month.

    He was the one that was a major factor that killed the A330X and then he wanted it.

    While I honor him for his aviation contributions (including Air and Space museum he has made his mark and time is passing him by.

  7. Ever since powered flight exists, the core of every successful aircraft, both in the Military, Commercial and Business Aviation IS the Propulsion System (Engine).

    We however in our hedonistic drive of technological hoarding, tend to take the Basic Systems in our Life as granted and do not allocate the necessary attention to these Basic Systems and their development.

    We talk more and focus more attention to rather unimportant systems, like IFE, Seats, Galleys, Paint Schemes…

    So why are we surprised that Propulsion System Manufacturers are struggling?

    We became completely oblivious to the complexities of Propulsion Systems and hold them responsible based on similar principles as applied to those who bake bread or print books.

    • I think Boeing might have to build their own engines. Issue challenging technical and timescale requirements on a product that requires massive investment and risk,is sold at a loss and then demand part the parts and maintainence income pie.Didnt GE have to contribute to the cost of developing the 777 300 as well?

      • Maybe they’ll be one of the bidders if GE sells off it’s aerospace division if it comes to that…

          • Airmail act. It doesn’t literally forbid Boeing to acquire GE. However it does block vertical integration of airlines, airline aircraft manufacturers and engine manufacturers.
            So Boeing could buy GE, but in that case no US airline could buy a new Boeing with GE engines to use on passenger flights.
            In practical terms it blocks Boeing acquiring GE.

          • no, it blocks Boeing from acquiring an airline that hauls US mail. not a huge revenue driver anymore.

            and I have no doubt that Boeing could buy enough congress critters to get section of the air mail act repealed.

      • Grubbie: Not happening. All 3 engine mfgs happy to submit. Boeing can;’t just come up with an engine industry pulling it out of their hat. Even if they bought one of the big 3 it still would be 10 years before first product.

        Ferenc: The engine mfgs are fully focused, they could care less about IFE et all.

        High standards have been set, technically we had achieved a nirvana state where the materials and tech were mature and they had a solid approach.

        Now Airframers wants a lot of improvement to launch, engine mfgs have to keep making engines but the materials and tech to get those improvements are a tough row to hoe.

        As there are only incremental improvements in air-frames, the big improvement is theoretically possible in engines, but its not easy.

        The one big one was GTF, but GE and until recently RR discounted it.

        P&W has not had a major engine program in some time and not in the quantity required for the A320NEO (and a few stray odds and ends for the C Series, MC21, Embraer)

        While they did not go high material tech, they did have to make a lot of engines quickly to match never before seen numbers (even if you only get half the A320 markets that is more than 10 years ago for all A320 and 737 production).

        That there are issues is to be expected. GE should have had fewer but they have had theirs as well.

        And as all 3 engine mfgs have seen, until you get it on the wing all your testing is only an indicator.

        RR got bite quite late, though they seem to have been asleep at the wheel on that one.

        • GE is having certification problems on its GEnx for the 787-10, and there is about 1 plane per month coming down the line with that engine and are supposed to be ready for delivery now.
          Looks like they will have to twist the FAAs arm some more as the plan was for that software bug to be fixed this time NEXT YEAR.

          • Can you site any specifics? I am hugely sckipti as the GenX is not a special version for the 787-10

            The RR Trent 10 is a mostly new engine (keeping 25% from the 1000 but all the bad parts from the old one of course)

            You should note that RR had to twist the EPA arms on a waiver for excess emission on the Trent 10 and next year before they get it fixed.

          • Rolls Royce and EPA?
            Wasnt the Trent 10- another TW flight of fancy

            “MTU America Inc., a Michigan-based subsidiary of Rolls-Royce Power Systems AG, is accused of selling 895 nonroad heavy-duty diesel engines — used in mining, marine and power generation vehicles and equipment — without valid certificates of conformity.”
            Isnt that your ‘expertise’ heavy duty diesels??

            They bought the German based company in 2014 , so those are largely historical issues for testing procedures with what used to be known as MTU and Detroit Diesel amoung other brands


          • Duke: I actually have quite a number of areas I am expert in, Diesels just happens to be one.

            I don’t see your point though.

      • US law does not allow Boeing to buy an engine maker nor build engines for its own airliners.
        This is specific for airliners (for instance does not apply to military aircraft).
        Boeing, P&W and GE are also not allowed to buy an airline (and vice versa).

        • If I remember my history, this stems from Boeing, United and P & W all being one years ago. Because of technical and industry advances, and a very different political environment, I can’t help but wonder if these laws could be challenged today. Not that I agree with monopolies and so forth, but you just never know… It could be a case to go before a “stack” Supreme Court… If the economy gets bad, and a bankruptcy rears its ugly head, one could expect the unexpected.

        • None of the military airframe makers owns an engine maker either.
          Another reason for the split up of United Aircraft and Transportation in 1934 was the new Roosevelt government prohibited airmail contracts to any airline that also built aircraft. The western half of the company which was Boeing and Stearman become one business while Pratt, Vought, Sikorsky and Hamilton Standard in the east become another and United Airlines was the 3rd.

          • Hello Bilbo,

            Regarding: “chapter and verse please. references are needed.”

            See the link below for the Air Mail Act of 1934, which starts at the bottom of page 933. Ownership restrictions are on page 936. I have not read through this carefully, but based upon a quick skim through, it seems to restrict only what holders of air mail contracts can own, and who can own holders of air mail contracts. Skimming through, I didn’t see anything about whether an aircraft manufacturer could own an aircraft engine manufacturer.

            I regards to this subject , note that conglomerate Textron owns both aircraft manufacturer Cessna and Avco, and that Avco owns piston aircraft manufacturer Lycoming, which makes engines for some in production Cessna aircraft (Models 172, 182 and 207).


        • I call BS.

          Boeing and United broke up because congress passed a law saying no airline that also manufactured aircraft could have a mail contract.

          that doesn’t prevent engine manufacturers and airframers from merging.

          nor would it prevent Boeing from operating an airline, just that that airline would not be able to haul US Mail (which is an ever decreasing revenue stream)

          Given that Boeing is the only US based commercial aircraft manufacturer, they would probably not even face anti-trust action.

          • Seeing as how FedEx delivers Post office packages you might want to rethink that.

          • FedEx doesnt carry passengers.

            The anti trust provisions came about because Boeing wouldn’t sell the 1st 60 of its revolutionary 247 model to anyone other than Boeing Air Transport.
            As Boeing is the only passenger airframer left in the US, buying an engine maker reduces competition in the market for turbo fan engines. The airlines and the other engine makers would raise merry hell .

          • Boeing is already (almost) exclusively GE anyway. there wasn’t even any competition for the MAX & 777X engine contracts, LEAP and GE9x were the only engines they even considered.

  8. While on the engine front, was wondering at what point an engine in the 50-60Klb range could be good enough, after aerodynamic penalties have been accounted for, to say power an 4 engined stretch of the 77X or 350K. Except general safety aspect during take off for an 400+ seat aircraft is that an 4 engined aircraft could potentially follow more direct routes due to lesser ETOPS restrictions.

    The A340-600 had an MTOW of 380T with Trent 556 (56-61Klb) engines, the 35K has an MTOW 316T and the 779’s will be ~352T. Such an engine could also have application for a new aircraft with 250-300 seats and range of 5000-6000Nm, MTOW 160-180T?

    • The ETOPs limits are set to long now that it makes no difference on all but maybe a few non flown routes (if any)

      Its only when your engines are junky like RR and the Trent 1000 that you get into those issues again.

  9. Read a month or so ago that both the Engine Alliance and RR are not over keen to continue production of the GP7200 and Trent 9000 due to low production rates of the A380.

    This is a bit of a “chicken and egg” situation but could the T7000 be an option for the A380(Neo)?

    • Its 7000 lb thrust short and has an almost certain flaw from the Trent 1000

      And it would require a whole new certification flight test, not to mention integration costs on a program that is going no where.

      Issues is not production rates its limited market and the costs Emirates want to have RR or GP put into it. Emirates obviously did not get out of the 900 what they wanted (or were promised)

      So no, its not going to happen, they are stuck with the 900 or GP options.

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