baobab72
5th Aug 2013, 03:07
Hi folks
I am a plank driver with a keen interest in helicopters and while i was watching a video on you tube on how to start different turbine helicopters i have noticed that in the vast majority of them - r66, bell206 and nh500 - the pilot briefed that in case of a hot start he would have closed the throttle and kept the starter button pressed in until the itt or equivalent would drop below a certain number of degrees stressing the fact that whatever happens do not let go on the starter button!
Now my question, although it might sound silly, is why doesn the starter switch lock in the engage position as it does on all jet engine airplanes - a speed sensing switch disengages the starter at a preset n2 once the engine becomes self sustaining - to prevent the pilot from accidentally disengaging the starter which might potentially lead to a hot start or in case of a hot start to prevent the engine from being cooled by the air rushing through it?
Many thanks
Baobab72
I am a plank driver with a keen interest in helicopters and while i was watching a video on you tube on how to start different turbine helicopters i have noticed that in the vast majority of them - r66, bell206 and nh500 - the pilot briefed that in case of a hot start he would have closed the throttle and kept the starter button pressed in until the itt or equivalent would drop below a certain number of degrees stressing the fact that whatever happens do not let go on the starter button!
Now my question, although it might sound silly, is why doesn the starter switch lock in the engage position as it does on all jet engine airplanes - a speed sensing switch disengages the starter at a preset n2 once the engine becomes self sustaining - to prevent the pilot from accidentally disengaging the starter which might potentially lead to a hot start or in case of a hot start to prevent the engine from being cooled by the air rushing through it?
Many thanks
Baobab72