Engine Start Malfunctions:
Dry Start:
- No fuel flow
- Low engine RPM (driven only by the starter motor).
- No light-up
Wet Start:
- Some indicated fuel flow.
- Low and stable RPM.
- No EGT rise.
After a wet start a "dry run" or "blow out" is carried out with HP shut-off valve closed and the igniters off to blow out fuel (if any) from the combustor.
Hung Start:
- Low fuel flow.
- Low and stagnating RPM.
- High EGT
Starter motor will continue to turn the engine but without assistance from the engine itself, the start will "hang" with the engine RPM stagnating at typically less than 20%
Often result of low air pressure or voltage to the starter motor.
Similar indications can be caused by a compressor stall or surge during the start cycle.
Hot Start:
Light-up followed by a rapid rise in EGT.
Usually caused by excess fuel in the combustor.
Spero questo ti sia d'aiuto a capire....
