Originally Posted by
mnjmc
Just trying to find some info on the why a gas turbine engine might fail to stabilise at idle on start-up, and what actions a pilot should take if it occurs. Thanks in advance!
What exactly do you mean by "fail to stabilize at idle"? Doesn't reach idle, keeps accelerating past idle, rpm starts oscillating around idle speed?
There are a number of ways a start can go wrong - hung start (stops accelerating short of idle), hot start (exceeds start EGT), etc.
In most cases, autostart will take corrective action (assuming the engine is so equipped), if not the normal procedure is to cut fuel, dry motor for a period (typically 30 seconds), then try again (although there are some engine specific techniques that can come into play).
There have been cases where a crew started an engine with the throttle well forward of idle - which caused the engine to keep accelerating above idle. The obvious corrective action is to retard the throttle to idle.