Emirates asking for A380 engine enhancements

Emirates obviously wants some enhancements for their A380 engines - at least for the aircraft that should one day replace the first ninety. The last of these aircraft will be delivered in 2017 and by that time Airbus will have delivered around 240 A380 if all production slots are filled until that time. Well, obviously some of the ordered aircraft will be either delivered later as their deliveries are deferred (like for Virgin Atlantic) of won't be delivered at all (read: Kingfisher and probably Hong Kong Airlines as well as Air Austral).
Two engine manufactures share the A380 market: Rolls Royce and the Engine Alliance (50:50 JV between GE and P&W). Let's say both have around 50% of the market (actually, thanks to the large Emirates orderbook EA has a slight lead), then both manufacturers will have delivered 480 engines plus spares.
Now Emirates asks for a "propulsion technology crossover into the A380, in terms of what they’re doing on the 777X, the A320neo and the 737MAX”, says Emirates president Clark and claims that one of the EA partners will produce "wonders in propulsion technology" by 2020, when the A380 still should have GP7200 engines (and the Trent 900 of course as well). So he asks what the plans from GE and P&W are to improve propulsion efficiency of the GP7200.
my first question would be who of the two EA partners will produce these "wonders"?

• Does he refer to the GE9X? He should have a good knowledge about what GE is planning for this engine, although some questions arose around his comment that the engine would need water injection to be able to lift the B777X from Dubai year-round: read the first reaction from GE here, another one here. Clearly, the GE9X will be the state-of-the-art engine in it's class, encompassing the Trent XWB-97, as overall pressure ratio and bypass ratio will be higher and the use of CMC should save some cooling air, further elevating the core efficiency compared to the latest Trent engine.
• Or does he refer to the Geared Turbo Fan from P&W. From all what we know this engine defines the segment of the regional and  narrowbody engines for the years to come (closely followed by the LEAP engine family, of course).

Nevertheless which engine concept Clark has in mind, I wonder if the two partners in the EA are ready for a big improvement programme for the GP7200. Small improvements have already been made: today's GP7200 are better by 2% than original spec values. To improve the engine by any big (SFC percentage) number should be at least very costly, if not impossible without a change in architecture. But with only about 500 engines of the GP7200 sold by then there would be no hope for the engine program to ever produce a profit. So EA (as well as RR) will do whatever they can to avoid another large development investment in the engine. RR could on the other hand also offer a downrated Trent XWB, although this engine might be too heavy for the wing as it is today.
Last week , there was speculation in a german newspaper about what might be the A380 going forward plan from Airbus. Günter Butschek, Airbus COO speculated about "modifications" for the aircraft, Heinrich Großbongardt, a german aviation consultant, speculated about an A380neo. I guess in Hartford, Cincinnati and Derby this was not a fun-to-read...

EASA Directive for Trent 900

The EASA found an oil fire in the HP/IP turbine area to be the cause of the uncontained failure in the #2 Trent 900 engine of the Qantas A380 on Nov. 4. This is an outcome that was expected by experts. The AD dated November 10, 2010 can be found here.
But why does an oil fire lead the IP turbine disk to disintegrate? Let's talk about what (likely?, maybe?) happened in detail and step by step:

1. The buffer cavity between the HP and the IP gets contaminated with oil. Why this happened is pure speculation at the moment. It could have been a bearing that leaked, it could have been oil lines that leaked or failed or something else...
2. During the take-off and climb phase temperatures in the cavity are rising high enough to let the oil ignite.
3. The IP shaft gets overheated and fails.
4. The IPT disk, now running free without the IP compressor as a brake, accelerates in milliseconds as fuel is still pumped into the combustor. The bore of the disk is designed to withstand speeds that are up to, say, 40% higher than the speed at takeoff, whereas the airfoils are designed to fail earlier, at maybe 120% speed. But the oil fire also heated up the bore, decreasing the so called overspeed burst margin.
5. The disk burst at a speed before the airfoils fail.

So what needs RR to do to prevent such a failure to happen again?

First of all, prevent the oil leakage. Without oil leakage no fire, no shaft shear, no disk burst.
Secondly, as you probably never can eliminate the possibility of an oil leak for 100% sure, a functionality has to be build into the engine that detects a shaft shear and shuts off the fuel immediately. Without the fuel being burned and the energy put into the turbine gas path, the disk will not accelerate.

Rolls Royce said that the Trent 900 and the Trent 1000 uncontained failures are unrelated. That might be true with respect to the causes of the two incidents. But I would like to hear what Rolls Royce changed in their design philolosophy between the Trent 900 and the Trent 1000 (and the Trent XWB) to prevent such an overspeed beyond burst limit speeds in case of a shaft shear as it appears that the outcome of the different causes was the same.
To clarify, the story I pictured is my view on what might happened. I can't assure that it was like I wrote. I hope to hear the "real" story tomorrow from RR.

Rolls Royce faces technical and legal battles

What a bad time for Rolls Royce:

August 2: Uncontained Failure on a Trent 1000 in Darby

August 30: Uncontained Failure at a Qantas B747-400 powered by RB211’s

November 4: Uncontained Failure at a Qantas A380-842 powered by Trent 900’s

Not to mention the more minor problems two B747-400 had with a RB211 (apparently a contained failure) and with fuel hydraulics.

And now: Pratt sues Rolls on patent infringement regarding the Trent 900 and Trent 1000 fan blades.

Let us recall: not long ago, in August, Rolls Royce filed a lawsuit against Pratt & Whitney, claiming that P&W would infringe their patented design for swept fan blades with their fan blades on the GP7000 and the PW1000G (and others). This case is due to go before a jury in the US in the first half of 2011.

Pratt & Whitney apparently fights back now, filing also a complaint with the U.S. International Trade Commission (ITC), which could be very damaging for Rolls Royce, as if the ITC rules in Pratt’s favor, RR could get blocked to ship any more Trent 1000’s to Boeing. And if the UK courts come to the same conclusion, RR would also have a problem to ship the Trent 900 to Airbus.

But could that be Pratt’s real interest? Not only P&W and RR would be deadly enemies forever, also Airbus and Boeing would not be happy about P&W, as deliveries for the B787 and A380 to customers with Trent 900 and 1000 engines would be (further) delayed or in the worst case impossible. As a last consequence you could expect RR to go bankrupt.

So I doubt that this is what P&W is really looking for – even if Airbus goes ahead with the A320NEO and P&W developing a version of their PW1000G Geared Turbo Fan for it without Rolls Royce, the two companies will still be tied for centuries, as the V2500 will continue to be shipped until 2015 at least and aftermarket activities will continue  - say – twenty years plus.

So what could be the real goal behind the legal actions?

My guess: P&W wants RR to “cooperate” a little bit more on the narrowbody front:

RR officially states that reengining the current Boeing and Airbus narrowbodies does not make any sense. But it sounded a little bit different until RR was officially put out of the reengining game by Airbus. And as RR has no interest to participate as  a junior partner in the GTF, RR would be out of the narrowbody market at least until a clean sheet design either by Boeing or Airbus arrives. So one can imagine that RR will do everything (legal, of course) they can do to prevent the Airbus reengining by hindering and blocking P&W’s PW1000G to be one of the –NEO engines.

I do not know how the IAE contract between Pratt, RR and the other partners looks like, but maybe RR can block an engine offering for the A320NEO by P&W – or block order conversions from the V2500 to a PW1000G once the A320NEO is officially offered to costumers.

It will be interesting to see how RR will come out of these two battles:

-          the technical battle: RR has to regain confidence on the Trent 900/1000 – and maybe the XWB

-          the legal battle with P&W

Picture of ruptured disk

Sorry, but somehow I cannot edit the latest post anymore - so here is the picture of the ruptured Trent 900 engine disk:

The Qantas A380 engine failure - a disaster for Rolls Royce?

A first serious incident happened with an A380 – the first Qantas A380, registered VH-OQA, made an emergency landing in Singapore, not long after taking off from the same airport.

Pictures show that the aft part of the No.2 Trent 900 nacelle is missing. Eye witnesses from the ground said that there was a loud bang (or explosion) and trails of smoke after that.

All this points to an uncontained failure. In recent months we saw two other uncontained failures in RR engines – first a RB211, also with Qantas, but on a B747-400 and then the Trent1000 on a testbed in Derby.

If at least the Trent1000 failure and the -so far- suspected failure in the Trent 900 of the A380 are in any conjunction remains to be seen. At least it is not good publicity for Rolls Royce in a time that is not easy for the No.2 engine maker:

• Deliveries of the Trent 900 are, due to the production problems and slow ramp-up of the A380, not in numbers that were anticipated in the business case. Any profit from this engine program is delayed by years (the same is also true for the GP7000, of course).
• Even heavier probably , the Trent 1000 drags on profit margins. The 787 is late by almost three years – if the first delivery in mid-February will be met. According to the original ramp-up plan, there should have been around 200 B787 in service by now, maybe half of if powered by the Trent 1000. The performance inprovement programs, aimed to meat the promised fuel burn at the aircraft probably doubled development costs.
• Development of the Trent XWB is in full swing, costing a lot of money, too.

So one could suspect that RR is running into a cash problem. Luckily there are the Trent 700, the leading engine for the A330, and the V2500 and Airbus upping deliveries for the A320. But if these two "cash cow" programmes can save RR in the long run, if there would be a main technical problem in the Trent 900/1000 (and maybe XWB), is questionable. A fundamental technical problem, a desígn fault, could end up in the grounding of the whole Trent powered A380 fleet. Qantas grounded their fleet of six A380 immediately after the incident, Singapore would be hit heavy with eleven A380 in their fleet today, Lufthansa so far took delivery of four aircraft.

It is too early to call today’s failure a disaster for Rolls Royce (and subsequently, for Qantas, Singapore Airlines, Lufthansa and, if the worst comes to the worst, Boeing and all their B787 Trent 100 customers) – but the possibility is there…

Update: meanwhile is is obvious that an uncontaines failure happened. Pictures are showing damage to the wing - Singapore Airlines effectively grounded their fleet also. Officially, all flights are just "delayed" until the engines are inspected, but a 100% inspection of the disks for such a failure would mean to take the engine apart...

Update 2:
Just found the preliminary report of the uncontained failure in the RB211-524, which happened on August 30th. It can be found here.
The key observations are (quoted from the report):

• All of the turbine blades had separated from the IP turbine disk.

• Blades from the three LP turbine stages were either fractured through the airfoil section or separated from the disk.

• The LP stage 1 nozzle guide vanes were destroyed. The remaining LP nozzle stages were substantially damaged.

• The LP turbine bearing and adjacent phonic wheel and speed probes were destroyed.

• The IP shaft was severed towards the aft end.

This picture is obviously a part of a turbine disk that fell on the island of Batam - we will soon hear if it is also the IPT disk - at least all baldes are missing.

The Trent 1000 failure also happened in the IP Turbine. If now yesterday's failure also can be tracde back to the IPT, I would be happy not to be employed in Derby...