successful inflight start after eng fail...go or come back?
 

Dear Friends,

Given the following scenario, average airport, average alternate airport availability for a say short over land, flight. rather fair wx conditions, a 737 CL. Engine quits for no aparent reason, successful inflight start, do we continue or come back ? I personally would go back if I can´t find a reason why an engine failed(such as ice formation or a stall), even though I think if an engine quits for no explainable reason, chances are it won´t relight.

Anything written in your sops? Any experiences?

The thread is all yours...
SW.

No clues at all - fuel interruption etc,?

Does Boeing or CFMI have anything to say? :confused::confused:

2 cents
 

In my training, using your scenario, losing an engine shortly after T/O is a simple return to base, no need to attempt a restart.

boeing does not recommend restart unless required for performance reasons. why? because if an engine quits (especially for no apparent reason) something is majorly WRONG!

otherwise: depending on trackmiles to touchdown and number of engines i would consider it ok to continue to dest. but no need to push. of course a return or diversion will cost your company some extra money. but hey, how often do things like engine failures happen?

Agree. Something is not right. Fuel contamination? Go back. Unless, of course, the place you have left has just been overrun by islamofascists or something like that. Then drop into the first safe place en-route.

Do you have a written reference for that statement?

A simulator instructor for one of the Alteon operations gives his crews a scenario of a volcanic ash event, followed by dual flame-out. He "permits" the relight of one engine in the 737. He then restricts the N1 on that remaining engine to only 60% which puts the crew in a serious position with gear down and flap 15 for the subsequent one engine inoperative and half power on live engine for landing. His rationale is that volcanic ash ingestion will probably cause partial loss of power on an engine that has been relit.

While this sounds like all jolly good fun for the instructor but probably a pain in the bum for his hapless "students", I haven't seen in any publication, proof positive that a relight under these conditions may only result in low thrust being available.

Has anyone had experience of this phenomena? And is this simulator scenario just another one of those unlikely double jeopardy "scenarios" beloved by some whose profession is simulator instructing?

"Has anyone had experience of this phenomena?"

Yes, engine failed without any prior indication of problem, or obvious engine damage.

As per the Ops Manual recommendation of "No obvious damage" etc., relight was successfully completed, resulting in normal operation.

As a precaution, with the reasoning that it wouldn't have failed in the first place unless something was wrong, I returned to the departure airport.

Approaching the circuit, it failed again. (FCU problem with slow air bubble accumulation in a pressure chamber).

I rest my case your honour:ok:

Regards,

Old Smokey

I wouldn't necessarily go back, but an expedient (as opposed to immediate) landing at a suitable field might be worthy of some serious thought.

I believe the wording on the last 757 QRH I had was if a restart was REQUIRED. Theory being that with 180 minute ETOPS surely 10 minutes in a circuit would be acceptable risk.

Just as an aside, what do you think the Customers would make of a Flight which Pressed On whilst relighting an engine and then thought about the consequences after it failed again? (see previous contaminated fuel/bubble issue).

Since we're talking about double jeopardy, what if one of the aforementioned Customers got a bit nervous as a result of the situation and disposed of their subsequent cigarette in the bin, causing an uncontained cabin fire whilst the aircraft was halfway between LPLA and TBPB?

Would you want to be indulging in staff travel with your wife and kids on that particular excursion?

The data is clogged with similar incidents, many on Boeing planes, where the engines quit for no apparant reason (to the crew) and were restarted successfully. Later analysis showed the reason for them quitting was fuel starvation (missmanaged). So I doubt seriously that Boeing recommends one to leave them alone after such a mysterious cockup.