Originally Posted by
Larmo
Why do helicopters keep the engines running and blades turning while loading and unloading passengers...
From the mechanical side, the start and shutdown of an engine is the most detrimental to its useful life, especially turbines. The main points are thermal and lubrication issues.
Also most turbines have a max internal temp limit prior to start so if on a short turnaround may have to wait for it to cool before start.
W1