Answer:
Fuel flow at light-off above 200 PPH (pounds per hour) indicates impending hot start, normally less than 50 PPH.
Step-by-step explanation:
When referring to engine fuel flow during light-off in aviation, particularly in the context of turbine engines, the terms "light-off" and "hot start" are significant:
Light-off: This term typically refers to the ignition and initiation of the combustion process in the engine.
It marks the point where the engine starts producing usable thrust.
Hot Start: A hot start occurs when the engine temperature exceeds recommended limits during the starting process.
It can lead to potential damage or reduced engine performance.
The statement suggests that during light-off, the fuel flow should ideally be within a certain range to avoid the risk of a hot start:
Fuel flow at light-off above 200 PPH (pounds per hour):
If the fuel flow during light-off exceeds 200 PPH, it may indicate that too much fuel is being introduced into the engine during the starting phase, which could lead to higher temperatures and the possibility of a hot start.
Normally less than 50 PPH:
In contrast, the statement indicates that the usual fuel flow during light-off should be less than 50 PPH, suggesting a controlled and appropriate fuel introduction to ensure a safe and proper start without risking overheating.
Thus, Fuel flow at light-off above 200 PPH indicates an impending hot start, typically, it should be less than 50 PPH to ensure safe and controlled engine start in aviation.