|Quoting Matt72033 (Reply 2):|
arent they more likely to happen on the ground?
during times of quick acceleration and deceleration of the engine? i.e. during start, and on selecting take off power?
Compressor stalls on modern jet engines are most likely to happen at (1) quick acceleration and (2) high powersettings.
This means that during taxiing, you'll probably never encounter it (on modern aircraft) except if there is damage to the engine, perhaps by a bird strike, or even a big plastic bag or a trench coat that's been sucked in the engine.
A stall simply means that the pressure in the forward part of the compressor section (there may be around 10 compressor discs or so) is insufficient to achieve the higher pressure in the aft part of the compressor section. If a compressor section has a compression ratio of 10:1, this means that the air going into the section at 10 psi is compressed to 100 psi (fictitious figures). Now if for some reason, the airflow is disturbed and entry pressure goes down to, say, 3 psi (ie. there's not enough air going in), then the 100 psi on the other end may expand in a forward direction, which causes the surge (because the engine's not made for that).
As you can imagine, the two most critical times are indeed upon acceleration where you need a continually increasing amount of pressure, and at high power settings, where you also need lots of air pressure in the inlet to maintain the high power setting.
Hope that explains it a bit!