This guy came very close to an atrocious death :
http://www.flightsafetyaustralia.com/2014/03/properly-clear-of-the-prop/
When I was a kid, about 14 years old I went to work at the local airfield.
The instructor and student climbed in after completing the external checks and I was asked to swing the engine, it was a Cub without electrics. Once I pulled on the blade the engine fired up. The instructor shut the engine, got the student out and gave him a mouthful for leaving the mags hot while I was priming the engine. It was not nice to see the prop turning in front of me but I did not understand much. Years later I carried a colleague into an ambulance after he passed through the prop of a C-206.
There is a strict, or should be, protocol when at the prop. Wheels are chocked – check, Switches off – check, brakes are set – check, throttle closed – check, pull through. Then, Wheels are chocked – check, switches on – check, brakes are set – check, throttle set – check, Contact. Step backwards away from prop, then liaise with pilot re chocks being pulled.
Kinda same process if you are doing it solo. Saves you becoming mince.
That is why it is a pet hate of mine, when someone wanders up and tries to chat to you as you are going through these process’s. Can easily distract you.
At our airfield, when I was ten years old, a guy tried that with a C-150. He died.
I did not know him, but i still recall his name, probably because it left a lasting impression on a ten year old that they found one of his arms on the hangar roof …
Guess what I tell my kids about props …
Me thinks there are more unintentional prop accidents than from intentional hand propping, although I could be wrong …
Always gets my attention when I see someone manipulating a prop for non-starting purposes.
Most don’t realize that it’s just like a loaded gun : trip the impulse coupler and it fires …
airplane engines are dangerous to be around…. props as well as jet engines. only a few days ago a guy was sucked into a jet engine at Mumbay. Did not make a nice picture.
Michael wrote:
trip the impulse coupler and it fires …
Quit a lot of maintenance people turn the prop backwards for this reason if possible. That way you can’t trigger the impulse coupling, and reduce the risk. Some don’t agree with that though, mainly due to the fair of damaging the vacuum pump vanes.
Changes of damaging them is quite small IMHO, as the engine will kick back at unsuccesfull starting as well and sometimes during switch off as well. Also most manufacturers don’t consider this to be an issue.
Jesse wrote:
Quit a lot of maintenance people turn the prop backwards for this reason if possible
Including me !
Jesse wrote:
Some don’t agree with that though, mainly due to the fair of damaging the vacuum pump vanes.
Consider that the same vacuum pump can be mounted on a Left OR Right hand turning engine. So much for that OWT !
What many do not understand is how the impulse coupler actually works.
They are in fact very similar to the trigger of a gun : move it just enough to trip it and BOOM!
Consider that the same vacuum pump can be mounted on a Left OR Right hand turning engine. So much for that OWT !
The pumps I have been using (Tempest) can run backwards for up to 50hrs.
But yes I don’t believe there is any possibility of vac pump damage by turning the prop backwards.
