NTSB Tells Rolls-Royce to Redesign 777 Engine Parts

Last month, I talked about how the British Airways 777 accident and the Delta 777 incident had been connected by an interim report from the UK. The NTSB has, after review, agreed with these findings and is now requiring “urgent” action. But “urgent” is not as dire as it sounds. It does not require aircraft to be grounded, and it will take at least a year, most likely, before the work is complete.

The NTSB has told Rolls-Royce that it needs to redesign the Fuel Oil Heat Exchanger (where cold fuel passes hot oil and they cool/warm each other to proper temperatures) to prevent ice Frozen Engineaccumulation and subsequent blockage of the the fuel lines. You may remember that the hot oil wasn’t properly warming the cold fuel and ice was forming. This has, so far, only been a problem on the Rolls-Royce Trent 800 engines, though Rolls believes that this could ultimately have a larger impact after further research is done on icing for long flights at very cold temperatures. But that’s another story.

Rolls is working on the fix already and expects to have it ready within a year. Once the redesign is complete, airlines will have no more than six months to implement the fix. So if this is so “urgent,” why aren’t the planes being grounded? Well, procedures have already been put into place to help avoid these types of incidents, but the NTSB doesn’t think that’s a good long term solution. In the NTSB’s words:

While the procedures may reduce the risk of a rollback in one or both engines due to [Fuel Oil Heat Exchanger] ice blockage, they add complexity to flight crew operations, and the level of risk reduction is not well established. And because the recovery procedure requires a descent, the aircraft may be exposed to other risks such as rising terrain or hazardous weather, or the inability to achieve maximum thrust during a critical phase of flight, such as during a missed approach.

So while the fix they’re using right now does work, it’s not satisfactory in the long term. So should we worry about stepping on a Rolls-Royce powered 777? I wouldn’t. But it is clear that there are problems and it’s good to see them being addressed sooner rather than later.

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17 Comments on "NTSB Tells Rolls-Royce to Redesign 777 Engine Parts"

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Your graphics are always awesome and this one (the ice cube on the wing) takes the cake. I know this is a serious topic, but good monday morning chuckles here! Thanks!

Devesh Agarwal

18 months is a long time, and should set one thinking. However, we should balance this with the fact that there have been two incidents against a fleet of about 220 B777s powered by Trent 800s worldwide that have been flying for quite some time.

I have written to elicit responses from Singapore Airlines, the world’s largest B777 operator. Hopefully will have an article in the next two days.

It’s good to hear that these issues are being dealt with swiftly, although there is still something disconcerting about this. I buy the notion that a year-18 months is probably the soonest that the upgrades can be implemented due to the R&D and production/hangar time needed to make these changes. Nonetheless, 2 of 250 Trent 800-powered 777s comes out to just shy of 1% of the fleet that has already experienced serious incidents related to this issue (one of which, as everyone knows, resulted in a hull loss). Obviously, the actual percentage of flights affected is miniscule-negligible, but 1% of… Read more »

Zach and CF,

SQ – which I think is the world’s largest operator of 777s – made it clear that their 777 that have the Rolls Royce engines are not flying long-haul polar, and thus they will continue to operate it. The link to the FT site, where someone posted the article, is here.


The other concern I could think of would be CX, but CX’s 777-300ERs (which they fly HKG-JFK and previously HKG-YYZ, both which go over the pole a lot of the time) are all powered by GEs I think so there’s not a problem.


Any definitive list of airlines that operate 777s with Trent 800 engines? Thanks in advance!

Peter Harris
Air New Zealand operate eight 777’s with Rolls Royce Trent 800’s. They also use them heavily on the LHR-LAX route, which exposes them to the very low temperatures of greatest concern. The airline has issued the standard press release about compliance and new procedures. However, the general public are not aware of the unique nature of this problem. It would seem that airlines like AirNZ could greatly reduce the risk by replacing the 777 with the 747 on the vulnerable route, at least until Rolls Royce have resolved the issue and new parts are fitted. A definitive list of 777’s… Read more »
Flying Blue
Finally! Tnx God we have NTSB report asking some action to be taken.. I do agree we have a fairly small percentage of loss and also there are conditions to meet to make a plane vulnerable.. Can somebody explain me what temperatures are reached over the Polar? i see on the screens while flying non polar routes easily -50/-60’C, so i wonder what that would be.. Anyway, i found odd BBC and other media going public with this news: ppl don;t have insight knowledge.. anyway, not a big deal, people easily forget too.. if less people is flying now is… Read more »
Peter Harris
I’m sure that Rolls Royce, Boeing and each of the airlines operating the 777/Trent 800 combination must be dealing with some very serious insurance issues this week. The NTSB report makes it clear that preventative procedures may not be effective to avert the risk and that the only solution is a re-designed engine part. Given such a public statement, if there was to now be a significant crash caused by the failure of Trent 800 engines on a 777, can you imagine the claims that would be filed against Rolls Royce, Boeing and the airline for continuing to operate an… Read more »
Peter Harris
CF – Good point. Perhaps one of the reasons they did not ground the fleet is that it could have brought down Rolls Royce, which would not have made the development of the new component any easier! What a thought that someone in an Insurance office this week has calculated the increased risk of continuing to operate the 777/Trent 800 aircraft in the face of the NTSB release and the chance of another accident and then determined the cost of that risk to the airlines involved! ….I guess its just the value of the lives of 300 passengers x the… Read more »
Devesh Agarwal

Finally got the answers from Singapore Airlines and their confidence in the Rolls Royce Trent 800 engines. http://www.bangaloreaviation.com/2009/03/worlds-largest-boeing-777-operator.html.


“Rolls is working on the fix already and expects to have it ready within a year. Once the redesign is complete, airlines will have no more than six months to implement the fix.”

Hard to believe it was urgent, but that more was not being done about it. Good to hear they are working on a fix. It has been long enough that surely that is taken care of now.


Hey CF,
Do you have an update on this? How are supposed to be the new engines with the fix?