Delta 777 engine failure

[Highkeas]

From Associated Press


NTSB Investigating Loss Of Power On Delta Air Lines Flight.

The AP (12/19, Koenig) reports safety inspectors with the National Transportation Safety Board (NTSB) "said Thursday they are investigating the loss of power in one engine on a Delta Air Lines flight last month from Shanghai to Atlanta. A similar incident occurred before a British Airways crash landing...at London's Heathrow Airport" in January, "according to British investigators. Both planes were Boeing 777s equipped with Rolls-Royce Trent 895 engines, and in September Boeing recommended procedures to prevent ice from building up in fuel lines on long, high-altitude flights."
The Seattle Post-Intelligencer (12/19, Wallace) reports the problems during the Delta and British Airways flights "are giving air safety investigators cause for concern." On Thursday, the NTSB "noted the apparent similarities with the British Airways event." Britain's Air Accidents Investigation Branch, "which has assigned a representative to the Delta episode, is working closely with the NTSB 'to determine if there are issues common to both events,' the safety board said."

[Dmmoore]

The definition of an engine failure is usually related to a mechanical defect that renders the engine unusable. Any accessory failure or fuel restriction causing a power loss is not an engine failure.
An engine flame out is reported as an in flight shutdown.
An engine failure requires an engine change. An in flight shut down is either caused by an accessory failure (fuel pump or engine control unit) or a precautionary shutdown by the flight crew.
An engine that stops producing power has not necessarily failed.
In this case the correct heading should be "Power Loss".

[E-Diddy!]

An engine that stops producing power has not necessarily failed.

That point could be argued

[mawheatley]

Same Country of Origin

Interesting point here is that both aircraft originated in China. BA uplifted fuel in Beijing, DL fueled in Shanghai.

I know they checked the fuel at LHR and there was enough still left, and it did not appear to be contaminated, but surely any water would have separated out, leaving a fairly pure jet fuel for testing? Two incidents in less than a year?

Common factors, admittedly, are same A/C, same engines, but let's not discount same fuel source.

[Cargo Runner]

To have any comparison between the BA and the DL flights you would have to lay the a/c over the other to see if there is any similarities.

Flight Path
Height
Time of day/year
Temperature

and a lot more, there maybe some over lays, but I don't think it will identify the real problem. I would be very interested to see the overlays and look at where the problems occurred

[LRJet Guy]

An engine that stops producing power has not necessarily failed.

Not sure me, or any other flightcrew member would agree with that.

[Spad13]

Not sure me, or any other flightcrew member would agree with that.

I'm with you there. It's not like there's time to figure out whether the thing "all the way failed" or maybe "just kinda failed". That's for the wrenches to worry about.

[cegro27]

His point is that an engine that has lost power in-flight can possibly be restarted, the pilots do have time to determine if that's the case. But if the engine has actually failed (such what might occur during an engine blade separation or bird strike), then the engine is physically damaged and can't be restarted. A power loss, such as a flame-out or compressor stall, can be corrected by attempting to recover or restart engine. A failure, such as a fan blade snapping off (and maybe penetrating the engine casing) will leave the engine totally inoperative. What happened to this Delta flight was a power-loss. The BA flight experienced a power loss as well, the only difference was the crew didn't have time to determine whether the engine could be recovered/restarted. In basic terms, a failure can be either or, but technically there "is" a difference.

[Dmmoore]

There are several categories when reporting engine problems to the FAA or manufacturer. The in-flight shutdown rate includes all causes of shutdown's. A compressor stall where normal engine power output is restored by retarding the throttle, stabilizing the engine and reapplying power is not counted.
Engine failure rate is calculated from engine requiring replacement.
Anytime an engine flames out or is shut down for cause, the engine is shut down or you have an engine out. Argue all you want but according to the FAA. it has not "FAILED" if it can be repaired on wing.
I have seen several replaced engines classified as "FAILURE" be reclassified as a repair when the bleed system was found to be defective, correcting the defect restored the engine to operational status.
So a pilot has an engine out. It's no producing power and you have procedures to deal with it. If the engine is running at reduced power such as were both BA and DL, they have not technically failed, even though the power output is not sufficient to maintain flight.

[LRJet Guy]

There are several categories when reporting engine problems to the FAA or manufacturer. The in-flight shutdown rate includes all causes of shutdown's. A compressor stall where normal engine power output is restored by retarding the throttle, stabilizing the engine and reapplying power is not counted.
Engine failure rate is calculated from engine requiring replacement.
Anytime an engine flames out or is shut down for cause, the engine is shut down or you have an engine out. Argue all you want but according to the FAA. it has not "FAILED" if it can be repaired on wing.
I have seen several replaced engines classified as "FAILURE" be reclassified as a repair when the bleed system was found to be defective, correcting the defect restored the engine to operational status.
So a pilot has an engine out. It's no producing power and you have procedures to deal with it. If the engine is running at reduced power such as were both BA and DL, they have not technically failed, even though the power output is not sufficient to maintain flight.

The only argument is who views it as what. In engineer speak, you are correct. Pilots don't speak that language though.

I've bagged four engine altogether. An R-985, restarted. Two IO-360, one was a precautionary shutdown, the other quit, and a CJ-610, never actually stopped running, just stalled, and we recovered from the compressor stall.

In my mind, since I was flying on one engine each time, they were failures. The bastard FAILED to run for the whole flight. In FAA / engineer speak, they aren't failures.

Happy New Year.

[Spad13]

In my mind, since I was flying on one engine each time, they were failures. The bastard FAILED to run for the whole flight. In FAA / engineer speak, they aren't failures.

I agree. Thrust thingy no worky - engine failure.

[Crunk415balla]

If the engine on my 172 stops providing thrust for my airplane, then I'd say its out.

[rohank4284]

The definition of an engine failure is usually related to a mechanical defect that renders the engine unusable. Any accessory failure or fuel restriction causing a power loss is not an engine failure.
An engine flame out is reported as an in flight shutdown.
An engine failure requires an engine change. An in flight shut down is either caused by an accessory failure (fuel pump or engine control unit) or a precautionary shutdown by the flight crew.
An engine that stops producing power has not necessarily failed.
In this case the correct heading should be "Power Loss".

Ok I agree with your book definitions of an "engine failure." However, like others have said when the engines are no longer providing power in-flight, putting the pilot and passenger in a perilous situation, also probably qualifies as a literal definition of an engine failure. Another interesting thing that already been brought up, is that both of these flights originated in China, so maybe tainted fuel could have been the problem.

It just seems strange to me that the RR Trent 800s have been powering Boeing 777s for over 10-12 years, through all sorts of weather conditions, and then all of a sudden you get two jets that had an engine shutdown during the flight in less than a year. If this were that common a problem shouldn't it had surfaced earlier? Or does heavy use of these engines make them vulnerable to such problems? This is why I think investigators have to look at the fuel provided in China. In addition, as others have said, a closer look at flight paths, temperature, cruising altitude could also help solve this mystery.

If the RR Trent engines are prone to such a failure, is it possible to put an anti-icing agent in the fuel to prevent icing? Also, if the RR Trent engines are at fault, Boeing and RR will probably have to make some engineering changes.

Regards,

Rohan

[Theoddkiwi]

In my mind, since I was flying on one engine each time, they were failures. The bastard FAILED to run for the whole flight. In FAA / engineer speak, they aren't failures.

This is why us engineers find it so hard to fix anything reported by flight crew.

The number of times we have had to chase up a pilot who has written up a defect in vague manor, then jumped out of his plane a run away before explaining it to the engineers is stagering.

I'm with Don, these engines have were operating at a Degraded Performance, still running but not very well.

Failure means something has stopped working!

[cegro27]

On the subject of DL, 777's, and engine failures/faults, it seems the fan disk on the right engine of a DL 777 blew apart on it's takeoff roll in ATL (#55, ATL-NRT) Jan 2nd I believe. The 'Soaring Spirit' is grounded for a while.