Article: NTSB: Emirates 777 continued flight after loud bang, messages
 

source

By John Croft

The US National Transportation Safety Board revealed in a preliminary report issued 30 August that an Emirates Boeing 777-200ER crew continued a 5h flight from Moscow's Domodedovo airport to Dubai on 5 March after hearing a "loud bang" and receiving several error messages on departure.

Pilots of Flight 132 (A6-EMH) reported the incident after landing at Dubai, according to the General Civil Aviation Authority (GCAA) of the United Arab Emirates, the authority handling the investigation.

"Following the bang a number of status messages were annunciated, these messages occurred over a 16 minute time as per the Boeing AHM (airplane health management) data," the report stated.

Messages indicated a problem with the right Rolls-Royce Trent 800 engine, and included a thrust asymmetry compensation message that is issued when the flight control computer automatically uses rudder input counter the yaw effects of a failed engine.

Four additional messages were received on departure, followed by two AHM messages after landing.

Flightglobal's ACAS database shows that the 14-year-old aircraft is owned by Veling and has Trent 884-17 engines, members of the Trent 800 family. As of 31 June, the aircraft had accumulated 61,581 cycles and 12,945h, according to ACAS.

Inspection of the aircraft in Dubai revealed "a large section" of the right engine's inboard fan duct and thrust reverser were missing, starting at the trailing edge and ripping forward.

Overall, officials estimated that 2.8-3.7m2 (30-40m2) section of engine covering to be missing, along with the primary exhaust nozzle outer skin. The primary nozzle inner skin had been "holed in several locations at the 12 to 1 o'clock position," the report stated.

External to the engine, the one tyre on the main landing gear "was observed to have a large cut to the sideway" of approximately 36cm (14in), officials said. Examination of the aircraft and engine was to continue but the results have not yet been posted.

The report does not discuss what procedures the Emirates crew followed after hearing the bang and receiving the AHM annunciations or whether the aircraft should have been returned to Domodedovo.

I note it says "status" messages. It could very well be that none of these had an associated abnormal procedure, so the implication in the article that the crew ignored something they shouldn't have is a bit naughty.

Sounds like something happened, the aircraft systems noted it, but it never was determined (by those systems) to be serious enough to post a message requiring crew action. And since the flight completed uneventfully, its hard to argue with that determination.

Messages indicated a problem with the right Rolls-Royce Trent 800 engine, and included a thrust asymmetry compensation message that is issued when the flight control computer automatically uses rudder input counter the yaw effects of a failed engine.

What does the QRH procedure say?

Unusual utilisation?
 

Average of 13-minute flight time. Or maybe it's block time, in which case DXB is amazingly efficient.

A lot of training flights?:rolleyes: Sim broken?

If Boeing uses the term "status message" in a manner consistent with us (or is that vice versa) I'd guess "nothing at all" - status messages don't require crew action.

61K cycles as quoted is highly suspect. Aside from it being well beyond the base DSO of 40K, that figure is well out of the ball park for a 14 year old long-haul aircraft.

I think its the FH number that is bogus too.

14 years is 122 640 calendar hours. 12 945 FH implies the plane is being used only 10% of the time. Unless its a hangar queen, that seems impossible.

Bets on it being 61k hours and 13k cycles? That'd be 50% utilization and 2.5 cycles/day which sounds more credible.

It would be 61k hours, and 13k cycles, sounds about right for an aircraft that also does short hops around the ME and into Europe.

That works out to be an average utilisation of around 12 hrs a day, which also sounds about right.

Since when journalists knows how to assess a 777 Non-Normal situation better than a trained crew!
Status Messages = no actions required and no troubleshooting either. Only maintenance on ground can take care of a Status messages.
Cycles are important, but maintenance in ME is probably one of the best in the world!
This episode won't affect the almost clean T7 record!

What date? That'll be the 1st of July then:ugh:

According to Aviation Herald, here are some of the status messages received:

You be the judge....

...Gladly.

There is no checklist or remedial action required for status messages. They are for information and maintenance action.

What are you suggesting should have been done? Shutdown an engine in defiance of the Boeing Bulletin specifically recommending against it? Divert when there was no actual non-normal situation?

I'm judging they did exactly as they were supposed to....

Well, I AM a 777 pilot and....

Consider? Certainly. I believe MCC was contacted by SAT PHONE, the situation assesed, and the decision that it was safe to continue made, resulting in a safe landing at destination.

No, the situation was not typical and thus required management, which was done. Are you suggesting anytime ANYTHING unusual happens, a return to origin is required?

Where exactley is anyone (and grizzled, you are doing so by implication) getting the idea that anything other than a professtional job was done?

ETA, for some reason this post keeps appearing before Check Aiormans post, even though it was written in response to it!!

I am not typed on the 777, thus cannot (and will not) judge the crew. However, for the experienced 777 crews, even though no action is required for status messages, wouldn't the appearance of multiple messages connected to the engine cause you to consider returning to the airport?

My rationale would be that it wouldn't be the first time a computer system generated seemingly innocuous messages when a more serious problem existed.

Is it typical of the plane to generated multiple status messages during flight?

Thanks for that reply.

I'm not saying that any fault requires a return, but I would certainly let the PIC know that I'd have reservations about continuing the flight. If he elected to continue, I'd be paying extra attention to possible en-route alternates just in case.

And to be clear- not saying the crew did not act professionally. I'm just trying to get a deeper understanding of how these situations are dealt with.

Wizofoz,
You sound like a decent EK trainer, who is appropriately rated on the T7, unlike some of the armchair pilots we see here on this forum.
Pray tell me then, what EICAS messages do you get on this airplane between 80kts and 400 ft AGL...??!!
I think the answer to my question should answer your query WRT the lack of eicas msgs and the presence of status msgs only.
Why then was the airplane dragged thru 5 hours of a trip.
Who was trying so desperately trying to get the plane 'back to base'. Which one of the 2 morons on the FD was trying to brown nose him/herself into the managments pants to enable a promotion...
And at what cost.
Last but not least, what was 'managment's' advice on ACARS when the AHM msgs hit home...
All wonderful questions, with dubious answers, I am sure..

Some posts missing.....this one written before post #13.
Still doesn't answer my question.

After take off a bang is heard and several status messages (all related to the engine) pop up...
The identification phase surely tells you that the bang is related to the engine as the status messages confirm, so why continue the flight knowing there is something wrong with the engine?!
Maintenance will always want the aircraft back home... its the crew in the end who decide..

Wizofoz...

Re: Huh??? All I did was provide some clarity to the discussion by showing what some of the actual status messages were (at least according to Av Herald). Your response suggests you are a tad sensitive re this particular event. FWIW, I certainly am not hung up on it one way or the other.

When I have something to say (on pprune or elsewhere) I say it. I don't imply. Sheeeesh....

loud bang
 

As a RATED Pilot on the 777, any "loud bang" followed by any status msg(s) would have resulted in a return to the departure airfield. Irregular status messages could have been managed and continued to destination, however these coupled with a "loud bang" is just waiting for the swiss cheese model to unfold!