Another A380 Woe?
The engine selection they need to do now will be for existing engines and for some current production A380 for early delivery from (IIRC) 2020.
The biggest limitations are hangar door size (which limits wing span) and hangar height. With the raked wing tips off the 747-8 has the same span as classic 747 and the vertical tail is essentially identical. The 747-8 is only about 8 feet longer than the 777-300 and that additional fuselage length is (generally) not an issue.
But there's no fundamental reason why an engine, or at least an engine family, can't be targeted at both big twins and 4-holers - the PW4000 and CF6 have done pretty well in both markets, for example, even arguably the GEnx.
The GEnx is shared between the 787 and the 747-8, but the requirements were enough different that the engines are far from identical. Relative to the -1B on the 787, the GEnx-2B on the 747 has a ~7 inch smaller fan, the low compressor (booster in GE lingo) is completely different with one less stage, the LP turbine is completely different, and the gearbox is completely different (to accommodate an IDG instead of the two big starter/generators on the 787) . Only the HP core is common. GE spent a boatload (well into 9 figures) developing the -2B from the -1B.
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May be a silly question - but what sort of number of airframes would get an engine manufacturer to think about this kind of development?
The difficulty is that, apart of course from Emirates, the A380 purchasers have only bought the aircraft in relatively small numbers. If it's expanded, particularly in cabin size, those same carriers would be the principal market, and they wouldn't want to have two small subfleets that were not interchangeable on their routes. There does appear to be no secondhand market. Although British Airways, for example, might be interested, it would really only be maybe a dozen more as a top up, and then they would end up with two different fleets.
That's not necessarily a problem for a sub-type with additional capability. BA has more than 50 777s, but only a dozen of those are -300ERs.
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The GEnx is shared between the 787 and the 747-8, but the requirements were enough different that the engines are far from identical. Relative to the -1B on the 787, the GEnx-2B on the 747 has a ~7 inch smaller fan, the low compressor (booster in GE lingo) is completely different with one less stage, the LP turbine is completely different, and the gearbox is completely different (to accommodate an IDG instead of the two big starter/generators on the 787) . Only the HP core is common. GE spent a boatload (well into 9 figures) developing the -2B from the -1B.
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No. That's the problem. There are no engines available that fit their requirements, and it appears increasingly likely there won't ever be. So they either convert the order to the classic A380 or cancel the order and buy a different aircraft. Since Airbus was not able to deliver the promised aircraft, cancelling the order will not entail any penalties. Emirates previously cancelled their order for A350 without penalty when that aircraft failed to meet their performance promises, so this is not something new for them.
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[QUOTE=Lord Bracken;10298996]Won't Mr Rolls sell you a Trent XWB -75 or -79 which fits the 75-80 rating with ease? You can even hang them on an A380, as Airbus have proven.
/QUOTE]
I believe the -75 and -79 were planned for the A350-800 -- a model that AB has dropped -- so these engines never went into mass production. Further, because these are down-rates of the -84 and -97 used on the A350-900 and A350-1000, respectively, it is likely that their performance suffers somewhat, and still may not reach the parameters that were originally promised to Emirates.
/QUOTE]
I believe the -75 and -79 were planned for the A350-800 -- a model that AB has dropped -- so these engines never went into mass production. Further, because these are down-rates of the -84 and -97 used on the A350-900 and A350-1000, respectively, it is likely that their performance suffers somewhat, and still may not reach the parameters that were originally promised to Emirates.
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Those finishing touches on a contract are the customer's big moment to negotiate some even better deal. EK have done it with Airbus before and it seems they do it with the engine manufacturers again. But they are on the record to be committed to the A380. So it's a matter of time not whether it will happen or not. Still interesting.
Problem is, that's not a certified configuration - and certifying a new engine installation is not trivial - far from in. First off, all aircraft performance must be redone and validated - many hours of expensive flight testing. Then the actual engine installation must be certified. Displays software will need to be updated. Aircraft handling will need to be re-evaluated, potentially including updates to the FBW software. Structural loads will need to redone and re-certified. Even ETOPS will need to be re-certified for a new engine (seriously). Probably somewhere in the $500 million to $1 Billion dollar range before it's all said and done to certify the re-engine - and that's assuming nothing on the engine needs to change (unlikely). Not to mention schedule - you're probably talking ~36 months from launch to initial deliveries - maybe longer.
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On the other hand FAA defines ETOPS a bit differently and in their system the term can apply to three or even four engine aircraft operating on routes with greater than 180 minute diversion time. Sigh.
Last edited by KenV; 2nd Nov 2018 at 11:03.
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Described here
https://www.airlineratings.com/news/...sir-tim-clark/
along with some hard words for Airbus, and more particularly the "engine manufacturers". A bit general, but I wonder who he is obliquely having a shot at. I seriously wonder if the offer of the EA engine on the next A380s, after it seems to have ended production, was a sales team initiative that production wouldn't do, and Emirates wasted time and money looking at it.
Worst damning from him is for P&W, who of course are not on the Emirates fleet.
“I’m not saying GTF is a failure, it should work, I am not altogether sure why it hasn’t worked ..."
https://www.airlineratings.com/news/...sir-tim-clark/
along with some hard words for Airbus, and more particularly the "engine manufacturers". A bit general, but I wonder who he is obliquely having a shot at. I seriously wonder if the offer of the EA engine on the next A380s, after it seems to have ended production, was a sales team initiative that production wouldn't do, and Emirates wasted time and money looking at it.
Worst damning from him is for P&W, who of course are not on the Emirates fleet.
“I’m not saying GTF is a failure, it should work, I am not altogether sure why it hasn’t worked ..."
He's just moaning that the manufacturers haven't invested billion just in case he gets around to buying a couple of engines.
Maybe he should look in the mirror and think about why people don't want to do business with Emirates, on Emirates terms, at any cost.
Still, Airbus and Boeing seem to have managed to overcome their distaste, to the tune of 500+ aircraft.