Airbus A330-800 and -900neo, first analysis part 2: engines and maintenance costs

Further to our initial analysis of the launched Airbus A330neo, here is our follow up diving deeper into engine matters and maintenance costs.

The A330neo engine

We met with Rolls Royce Vice President Customer Marketing Richard Goodhead to talk about the Trent T7000 for the A330neo and to straighten some misconceptions around the engine. First the base facts as presented by Airbus and Rolls Royce Monday:

Rolls Royce T7000 data

Rolls Royce T7000 data

Ignoring for a moment the red box (our emphasis), the engine is a straight derivative of the Rolls Royce Trent T1000TEN from the Boeing 787. The thrust- generating parts of the engine sees no changes, thereby our speculation that we might see the application of Rolls Royce ALPS (Advanced Low Pressure System) CFRP fan blades and fan case did not happen. We asked Richard Goodhead why?

“Even if the ALPS programs composite parts would be ready to go into the T7000 we would not see the weight benefits we have projected as part of this program for an existing engine using the technology,” Goodhead says. “To gain the 150-200kg weight gains we talk about, one has to design the engine from scratch with the technology. Applying it to a T1000 derivative does not bring the necessary benefits. The ALPS technology will see first application in our Advance engine.”

We then addressed the misconception that the 787 engines had to be “converted to bleed engines,” as widely reported in the press. We have been arguing that this is indeed a misconception: the 787 engines, both GENx-1B and Trent T1000, as operated today on the 787 are bleed engines. They bleed about 20% of the core compressor air for engine/nacelle internal purposes. This internal need is present on all jet and turbofan engines. They thereby provide cooling air to turbine stators and blades and the different nozzles. They also provide air for the pressurizing of the engine’s many rotary seals, present at all turbine stages.

For this purpose, there are bleed ports on up to 50% of the compressor stages, tapping just the right pressure and temperature air to the engines different hot parts, low pressure compressor bleed serving the low pressure turbine, higher pressure compressor bleed serving the intermediate turbine and so on. Adding another 5%-7% of air on top of the 20% in order to supply air for cabin air conditioning and wing deice will not be a significant change, in fact it will not require any new bleed outlets on the engines core.

“I can confirm that adding cabin and deice bleed to the Trent T1000 will be one of the simpler tasks when creating the T7000,” Goodhead says. “In fact it will require minimal hardware changes and the additional bleed will affect the engines performance with less then 1/10 of a percent. There are other areas requiring more of our attention, such as the significant reduction in electrical power served to the A330neo airframe compared to the requirements of the 787. The reduction in the drive power to the gearbox where the aircraft’s electrical generators are attached will cause hardware changes on the engines internals. This and the changed mounting of the engine (compared to the mounting of the T700) are more significant challenges for us and Airbus .”

Another subject we covered was the engines maintenance cost. The red box in the slide talks about comparable economics for Total Care services and LLPs (Life Limited Parts in the engine). We asked Goodhead what this all means.

“It means that an airline ordering an A330ceo or A330neo will be offered similar prices for our Total Care maintenance including Life-Limited Parts.”

This is significant as engine maintenance costs constitutes about 2/3 of total maintenance costs and the 787 engines have higher maintenance costs, according to our market intelligence.

Airframe maintenance cost

To this leveled engine costs, Airbus adds further improvements to the airframe maintenance costs.

A330neo maintenace costs

These include:

–        extending the A checks to 2,000 hours flying time

–        requiring 2C base checks at half the interval, now at 48 months

–        elimination of certain fatigue sampling tasks

–        conversion of the ceo’s pneumatic regulation of the airframe’s bleed air system to more reliable electronic regulation

Airbus is joining forces with its strategic partners to challenge one of 787’s strong points, its projected low life cycle maintenance costs.

Cash operating costs (the cash you pay for using the aircraft vs. leaving it parked)

If we look at the major cost positions for the A330neo’s Cash Operating Cost (COC) which can be affected by Airbus and its partners (crew costs is not within the OEMs domain to affect) we can summarize:

–        Fuel costs. Rolls Royce and Airbus will lower these with 12% for long haul operations. For short to medium haul the improvement will range from none to the full 12% depending on stage length. The difference in fuel consumption between a 787 and a A330ceo is in the 11%-15% range so this difference all but disappears depending on model, range and payloads.

–        Landing and underway fees. The A330-900neo has a lower Max Takeoff Weight (MTOW) than the 787-9 and these fees are governed by MTOW. Hence the -900neo will be charged lower fees than if the mission was flown with a 787-9. For the -800neo versus the 787-8 this picture reverses; the 787-8 has a lower MTOW.

–        Maintenance costs. As described, the engine costs differences shall be virtually eliminated between a Rolls Royce equipped A330ceo and A330neo. It remains to be seen how this will affect the engine maintenance costs for the 787; logically these will come under further competitive pressure. The positive airframe maintenance costs difference for the 787 will now be further reduced and as before they constitute only about 1/3 of total maintenance cost.

By Leeham Co EU

21 Comments on “Airbus A330-800 and -900neo, first analysis part 2: engines and maintenance costs

  1. As it is made clear in this article, the 787 engines are actually bleed engines that are adapted for the all electrical architecture of the aircraft.

    So they are bleedless engines only on the aircraft side. In other words it is the aircraft that is bleedless, not the engine!

    On the engine side, which consumes the larger portion of the bleed air produced by the engine, they remain conventional engines.

    We can say, for all practical purposes, that the 787 engines were actually “modified” to become “all-electric”. Not the other way around.

    The most important difference lies with the 787 engine gearbox which is extremely big and powerful in order to drive the enormous dual starter-generators required for the all-electric aircraft. This will have to be simplified for the Trent 7000. More than a few pounds could be saved there. In other words, the 787 engine gearbox is overdesigned for a conventional bleed engine.

    The task will not be easy though, for this gearbox is part of the design of the engine as it was originally conceived for the 787. It is a major engineering challenge. It is sometimes easier to start from scratch rather than modify an existing design that was conceived for a totally different application.

    It is not just a matter of installing a smaller gearbox. The dynamics of the new system will be very different and will impact other parts of the engine because the rotating mass will be reduced considerably. That is, among other things, why it can be considered a major modification.

    But Rolls-Royce has the technical wherewithal to overcome those difficulties.

    • The task will not be easy though, for this gearbox is part of the design of the engine as it was originally conceived for the 787.

      This mod suposedly has been done on the GE counterpart ( for the 747-8 ).
      Was it all that difficult?

  2. I think its disingenuous to say that the engine is actually a bleed engine and overdesigned electrically .

    They took the function of a modern jet engine and optimized it for the purpose for which it was intended which was to use electric power in place of pneumatic power.

    They put no more than needed for the starter/generators. Its not over designed all word cuteness aside.

    I also do not buy that they are taking 1/10 of a percent off to run the aircraft. Compressed air is power and if you use it for power purposes it has to replace the electrical power system. energy is no more free than taxes (at least for those of us who pay them, Boeing excepted of course which does prove there can be free launch)

    If that’s true then the more electrical architecture being efficient is truly a hoax (or cold fusion really doe work). And why would Boeing do that if it was not true?

    Power is power, it has to come from someplace. Direct is better than indirect (ergo more electrical is supposedly more efficient as well as the infrastructure through the aircraft using wires instead of tubes).

    And lastly, GE actually has a fully working true bleed air system in place without Generators on the 747, interesting to not utilize a well proven system.

    • I was going to type a long rebuttal. But, I think the article already does a brilliant job.

    • The 1/10 of a percent does not represent the penalty for siphoning air off to support the needs of the airframe, it is the penalty for using a less efficient compressed air path for the air conditioning system and the wings deice. The use of engine power for airframe purposes is present in both 787 and A330ceo or neo, the power is just served through different means.

      Boeing went the more electric way because they can make the conversion from engine level wild frequency AC to aircraft AC / DC more efficient (using Thales / Zodiac electronic power converters) than an equivalent A330neo conversion chain, taking engine level compressed air (to high pressure and to hot to route around the aircraft, therefore cooled and pressure reduced already in the pylon) to the usage level air driving the air conditioning system and the wings deice.

      In the process Boeing had to master a number of problems associated with new architectures, the panel arching and battery problems examples thereof.

      • Please let me congratulate you for the quality of your articles. It is always an immense pleasure to read you. And I would like to take this opportunity to congratulate Scott for recruiting you.

        PS: I would like to be able to put a name behind Leeham Co EU.

      • The wild AC is simply varying frequency due to the engines speed as alternator frequency varies with speed. Honda has done the same thing on small generators for many years (along with a host of other rectifier/inverter types including electronic GPUs at gates)

        All aircraft need batteries, its not the battery need that was the issue but the type they chose to use (and complete lack of oversight for the system)

        Also to be kept in mind is the hydraulic power needs (or replacing hydraulic power with spot hydraulic or even electric brakes)

        Probably the single biggest aspect is the wire size vs ducts as well as the ability to route wires in places you could not run ducts.

        Overall it would appear it’s a more efficient way to get power from source (engines) to point of use. I would guess moving electrons is more efficient than moving air.

        Personally I like pneumatics with the advantage of simplicity and trouble shooting but electric is hard to beat if its reliable. Boeing seems to have pulled it off.

    • I would avoid the GENx for the A330neo regardless of already being modified. The GE has the icing issues that caused more issues with the fix. The A330neo has quit a bit larger market in areas where the icing producing storms are found.

  3. Interesting perspective from Rolls Royce. Everyone likes Goodhead.

  4. Given the above and assuming you don’t need the range, why would anyone buy a 787 when they could get an A330 NEO for less yet have very similar COC?

    • From what I can work out the A330NEO’s will both have higher OEW Weights and lower MTOW weights when compared to the competing models of the 787. It will also be less efficient by about 3-4% (I am not sure how this number should be applied).

      If we consider the revenues (cash) for operating the aircraft comes from the weight between OEW and MTOW minus fuel, in theory the 787 should have a distinct advantage.

      Considering Airbus themselves have stated the A330CEO will be more economical over shorter runs (less than 2000nm) and the A330NEO will not have the range or payload capability of the competing 787 models, the 3-4% difference in operating costs being quoted may only be realised in a very narrow range (5000-6000nm) and payload (85%) window.

      I’d suggest part of the economics of operating A330NEO’s over 787’s is that of opportunity cost. If the cost of ten 787’s can purchase twelve A330’s, the profits from revenues (cash) generated by flying two extra planes may be greater than the costs saved by flying two less, but more efficient planes.

      I am still a little suspect about the 3-4% numbers being quoted. I’d suggest the appeal for this aircraft will be limited to certain airlines (LCC’s) in the market. On the same point I am a little confused by the interest shown by the lessors. Considering their profits will ultimately come from how the market values the aircraft, not operating costs per se, their orders suggest a reality very different to the one I have presented.

      We will have to wait and see!

      • Are you sure about that?
        “From what I can work out the A330NEO’s will both have higher OEW Weights and lower MTOW weights when compared to the competing models of the 787”

        The 787-8 has about the same passenger capacity as the A330-200 but the Airbus has a 14 tonnes higher MTOW and just a slightly higher OEW by 1.6 tonnes.

        The A330-800 tafkap A330-200NEO will have with 8,200 nm a greater range than the 787-8 using the same estimations as Boeing did to calculate the range. The official range for the A330-800 is just 7,450 nm.

        We have to add the new engines to calculate the new OEW difference but also we have to look at the weight for the complete new interior based on A350’s interior. LED lighting will save a few kg. Are there any numbers out there according weight difference between a single current A330 seat and a new A350 seat? I will not bet my money on the A330-800 to have a higher OEW than the 787-8 .

        “We will have to wait and see!”

        • Quoting mhalblaub:

          “The 787-8 has about the same passenger capacity as the A330-200 but the Airbus has a 14 tonnes higher MTOW and just a slightly higher OEW by 1.6 tonnes.”

          You have 787’s mixed up…

          787-8 OEW = 111,500kg (ish)
          787-9 OEW = 117,707kg GE + 117,798kg RR

          The A330 (Non neo)

          A332 OEW = 119,600kg
          A333 OEW = 124,500kg

          Thats a difference of:

          8,100kg for the 788/A332
          6,702kg for the 789/A333 (with RR)

          And that is before you add the 4-5t for the Neo, that Scott has suggested.

      • What no one is factoring in is if your 787 needs to fly a short 4000 mile segment, you don’t have to carry excess fuel (there may be factors like price you pay in one spot vs another and if there is mandatory regs in a country you have to buy fuel there that changes that as to being an advantage or not)

        As flight global also pointed out, fuel is traded for passengers all the time.

        Belly freight is a factor as well as an airplane is a revenue generating machine and if freight is part of that revenue stream, then the plane that carries more freight has a significant advantage as well.

        Throw in a specific airlines routes and then factor it all in and then it starts to mean something. That’s why its almost impossible to come up with a model because the varaitiosls between any two airlines are totally diffeent.

        UPS uses the 767s as trans pacific freighters. No one else does. They have a business model and plan that makes it work when it does not for anyone else. Its how you utilize and manage the asset.

        The least important factor is aircraft price. fuel saving easily pays back lower price (unless you are talking Delta and the 717s but they got them really really cheap and it’s the right size for certain route segments that a heavy A320 or 737 doesn’t cut it)

        All the factors aside, a full 717 is far more ROI than a 60% full 737/A320 .

        • Actually, what “No one” is calculating? is that the 787 is lost weight, while the A330neo is gaining weight… Forget the 800kg weightsaving proposal that AB is selling… It will still be 11-13t heavier then their competiters…

  5. Very nice post!

    Now, since the A330 was a modern airframe with dated engines, might at last see its true potential.

  6. The adavntages of a bleedless architecture have been discussed several times. My overall impression after discussions with knowledgable people is that the effect on cruise fuel consumption is neglectible, but other advantages/disadvantages exist (air contamination, power optimisation).

    I still don’t understand why you calculate the added weight of the engines as big disadvantage for shorter ranges. The engines will reduce the fuel burn from minute one of the flight. The added empty weight will have a small effect, which is less compensated by saved fuel on short ranges, but check the dimensions. An A330-300 CEO requires about 50kg of fuel to lift an extra ton for 1000nm, hence 2t extra OEW will cause 100kg extra fuel burn for 1000nm. The saved block fuel by 14% better engines is more than 1000kg (for a 1000nm trip). So the claim that the NEO is no good for “short” (i.e. 2000nm) ranges is wrong.

    • Assuming your calculation is correct, at 2000nm the fuel savings (2000kg) already compensate for the OEW increase, so there is no actual weight penalty once you include the fuel (since the A339 will need to carry 2t less fuel).

      At, say, 1000 nm, there would still be a weight penalty, but the lesser fuel burn will still compensate …

      • @Schorsch and thysi, please observe that this is not our statement, we are relaying what Airbus has said about 330ceo vs. neo on short range (Kiran Raos quotes last week, see our analysis part 1). We have not had time to look at this ourselves yet but will do, then we will give our opinion based on our independent analysis and modeling.

        • Will be happy to see your analysis!

          I guess the Airbus VP did not specifically address the fuel burn, but the fact that fuel in general becomes of lesser importance when ranges decreases as other cost (landing fees, ground handling, cycle-depending maintenance cost) start to dominate. While beating off a 12% advantage would require a very short hop.

        • Looking forward to the analysis, as always! A comprehensive model (with the various costs, not just fuel) at several different ranges would make most interesting reading.

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