Engine Failure and Shutdown - Restart?

[Stan Woolley]

Any thoughts about restarting jet engines given no fire or apparent damage.

Always? Never ? Ever done it and wished you hadn't/ were glad you did? etc

[aulglarse]

Stan, a broad question to answer.If an engine fails/shuts down, it has for a reason and sometimes for example, this may be due to a software glitch (no other warnings on the EICAM/ECAM).

If a failed engine is going to place the aircraft from an abnormal situation into an emergency one,say overflying a high LSALT area on one engine and no other options available, then a restart is justifiable.

Fortunately I haven't been in this situation....yet.

[Gin Jockey]

If able, I would discuss the prospect with engineering.

If there is no apparent damage, what is the worst that could happen? Even an idling engine gives you hydraulics, electrics and bleed air.

[N1 Vibes]

SW, aulglarse,

not a pilot, but an engineer - was riding an A330 annual certification flight-test, at FL200 100Nm from HKG over the Sth China Sea, when we found ourselves (me and 2 CX test pilots) with both engines failed/rundown and the RAT deployed.

First engine (#2 i think) was shutdown per FCOM due to IPT overheat warning in single eng climb at MCT. 2nd (#1) engine randown after a loud surge, when powered up after the single eng climb.

Decision was taken between myself and the 2 crew to restart the IPT overheat eng, for the exact reason you mention, since we would not hope to need to use any power level like MCT on our return to HKG.

As it was this was the best call coz a) we made it back! and b) the other engine would have likely surged and rundown again. (yes Gin Jockey, always handy to consult eng esp when they are sat behind you on the jump seat, with sphincter puckered! hehe)

Hope this was a good example.

Regards,

N1 Vibes

[BOAC]

Stan - certainly Boeing (on the 737 anyway) give crews the option and the QRH procedure. The rest is what we are paid for.:)

[Stan Woolley]

Thanks for the replies.

N1....... well certainly an interesting experience!

BOAC.....what if it isn't optional?

You still have N1,N2, no exceedance and no Fire/Overheat but you don't know why it stopped ?

[captjns]

Why did the motor stop working? Let engineering restart the motor when I am as far away from the jet as possible.

[BOAC]

BOAC.....what if it isn't optional? -Stan - it is always OPTIONAL in your example. Whether it is wise is.... (see last sentence). If it is relight or crash into the mountains, what would you do? You can always crash later.:) Engineering come further down the decision chain, captjns. Very few toolboxes have crashed killing people.

[Stan Woolley]

-Stan - it is always OPTIONAL in your example.

Rory Bremner doing Paxman...........'mmmmm...yes'

[Wizofoz]

Stan,

My gut feeling is that QRH procedures for re-lights are carry overs from old, low by-pass engines (JT3s and the like) that WOULD "Just flame out" from time to time.

I've never heard of a modern, High-bypass jet stopping for no good reason.

Like I said, just a read of the situation, not a definitive answer.

[Old Fella]

Captjns. Motors are used to start engines, similarly planes are for use by carpenters.

[Ashling]

Cases were all your engines stop and complex multiple failures, MEL restrictions aside if you lose an engine on a twin then its land as soon as possable. If restarting your engine would delay that approach and landing then it is a bad idea. A modern engine is v unlikely to fail so when it does it will be for a significant reason so it may well not restart in any case. If you have time before the approach then it may well be appropriate to give it a go depending on what you stand to gain from it. Thats a judgement call on the day.

If you have 3 or 4 engines then its going to be more complex depending on what your company SOPs and regulators rules are as you could opt to continue with one out. I would imagine a discussion with company engineering would ensue. Again if you choose to divert due to the failure do not relight the engine if doing so will delay your approach.

[ssg]

If your flying along on one engine, in a twin. and everything is ok, restarting could create more problems...studies have shown that increased variables for pilots increases incidents and accidents...if all is ok, just fly to your nearest alternate and land safely..

Conversely, if your over the mountains at night, white out conditions, descending on one engine, full power.., would crashing make more sense then restarting the engine only to find out you had some ice in the fuel line..?

You have to look at the situation and make a judgment call...

[SNS3Guppy]

I've never heard of a modern, High-bypass jet stopping for no good reason.


You've never heard of a JT9 failing in normal operations?

[FE Hoppy]

Must have shut down and re-lit speys about 500-1000 times. We did it as routine to save fuel on the nimrod.

As for relighting a failed engine on a commercial flight, forget it unless the other one is showing symptoms of failure.

Don't forget your flight is perf A. You always have drift-down performance to clear terrain/obstacles or an escape route planned.

If you don't know why it stopped you don't know what will happen when you try to start it.

Your ATM is one if not the fastest rotating parts on the aeroplane. Treat it with respect!

[RAT 5]

I've heard various ideas about this. Some have said that the idea is to land ASAP at nearest suitable airport. If the failure happened on departure, and Wx is suitable, then land back. QRH's etc will take 10 mins to be ready for approach; assuming familiar with departure airfield and not lengthy approach brief required. Why waste time attemting a restart and delaying the landing. Added to this, if with an engine that has flame out protection, why did it stop? Of course you don't know if the auto system worked or not!

If the failure occured in the CRZ why not attempt a restart if it does not cause a delay in landing. However, as has been said, consider it carefully. Some airlines have a policy that you will consider a restart; meaning try it.

It's a classic question where 10 pilots will have 10 opinions.

[frontlefthamster]

I've never heard of a modern, High-bypass jet stopping for no good reason. You've never heard of a JT9 failing in normal operations?

Neither of you have done as much research as you could...

If there is no sign of damage, a restart is a definite option, as is a restart followed by low thrust operation. The training world goes round this particular mark more often than Airbus pilot wonders whether he really an aviator any more...

It's a matter for each commander, but for my money, this is a no-brainer. Get it running again, if you can. In trying to do so, you'll find out whether you can or not. This may turn out to be valuable information. With it running, you'll have normal services available.

Modern engines DO sometimes stop without asking permission first (though contrary to one post above, 'computer glitches' are incredibly rare causes for this).

The next question is, having got it running, do you land asap or continue? On a twin? On a four-engined aircraft? In a remote area? Heading across an ocean?