Originally Posted by
stilton
Fixed wing pilot only here so indulge me
Currently reading ‘ guns & gunships’ by Mark Garrison who flew the UH1 in Vietnam
He mentions the common practice of hot refueling between sorties then, it saved time and he emphasized that it reduced the possibility of a hot start with a brief shut down leaving you with high residual EGT prior to restarting
That all makes sense and of course it’s easier on the battery and fewer engine cycles
Just out of curiosity though, can you not motor a helicopter turbine with fuel off to lower EGT prior to fuel on ?
Yes, you could engage the starter motor, pull air through the engine to cool the residual heat, but why would you want to go to the bother of a shutdown and restart just for fueling? "Hot" refueling, that is with the engine running, were routine.
Battery, weak starter motor, aggressive start settings and/or a mistake in the procedure- the pre-start required one to close the the throttle against the idle stop, click the stop off, roll through it and then guess where the throttle was just below the stop. My memory is that a lot of hot starts involved discovering that the throttle was above the idle detent, the start was going hot, the pilot would 'close' the throttle only to hit the detent and fuel continued into the engine as it exceeded limits; or the battery would be depleted by the time the pilot realized the mistake and tried to click through the idle detent to shut the fuel off.
I
hated flying other aircraft besides my assigned one. I knew my crew chief well, I knew the pride he and the gunner took in
THEIR aircraft, I knew the aircraft idiosyncrasies 'Spares' were often not flown with a regular crew who had a lot invested in keeping it top notch.
There could well be a lot of human fatigue in the equation as well, we worked day/night rotations- I was grounded for exceeding the maximum 30 day running flight time total for about half my tour. The running sum varied between 110 and 140 hours, and you have to remember that my crew chief and gunner were always along on the flights, they had pre- and post-flight duties. There were occasions when crew were running 24, 36 hour continuous flight assignments, snatching the occasional nap. I've had pilots fall asleep at the controls...