compressor surge/stall

[Ton van Bochove]

Today ( while climbing out with CB) I had a compressor surge/stall. First I thought the irregular sound of the engine had to do with the weather but getting into more stabile weather the sound remained. With a bit of cheating in the malfunction menu it was fixed ;-)

There are no Eicas messages so I assume a trained pilot knows the sound and acts accordingly.
- I cheated but what is the normal procedure? Stop the engine and do an inflight start?
- what causes this surge or stall, weather or are there any other circumstances

[Britjet]

There is a "Engine Limit or Surge or Stall" QRH item.
This starts with a memory item - which is to progressively throttle back in the hope that the unusual behaviour will cease. If you can achieve this then the procedure is to leave the engine running and continue on reduced thrust.

This might sound strange - the idea is to minimise the engine shutdown statistics. Having said that the crew would probably check with engineering at the first opportunity to see if it made more sense to shut the engine down.

If the surge or limits (such as EGT) remain exceeded, then the engine is shut down by the QRH. This does not preclude  little tricks such as selecting ignition to CON which might fix an engine which for some reason hasn't got correct airflow through it.

Peter

[Ton van Bochove]

Thanks Peter, it was not in the QRH index but I found it (7.12)

[Dirk Schepmann]

Interesting, I never had an engine surge or compressor stall in PSX inflight.

Perhaps my random failure settings are set too low, I'll have to check the manual and severity of the malfunction. Or can an engine surge happen even with malfunctions turned off?

Dirk

[Jeroen Hoppenbrouwers]

https://en.wikipedia.org/wiki/Compressor_stall

https://www.wisegeek.com/what-is-a-compressor-surge.htm

https://aviation.stackexchange.com/questions/57426/what-exactly-is-an-engine-surge-in-a-jet-engine-and-what-causes-it

https://www.youtube.com/watch?v=yaFeO6Jze64

[Hardy Heinlin]

Severe mode is "surge", non-severe is "stall".

"Surge" makes a loud bang and the engine flames out and fails completely.

"Stall" makes some softer bangs which will repeat at random, and the engine keeps running. The higher the thrust, the shorter the time intervals between the bangs. Each stall causes a momentary thrust reduction and a yaw impulse, which can be very violent on the real aircraft, according to pilot reports.

As far as I recall, the surge/stall malfunctions can only occur when they are set by the Instructor controls.


|-|ardy