Thursday, 26 January 2017

HAND PROPPING

Acknowledgemts: EAA Chapter 1000

Hand-propping is like stalls and spins - you don't learn much by simply talking about it ... PROP-SWINGING is a manual skill, and it should be learned by actually doing it, under the guidance of an already qualified and experienced person - it can't be learned by reading this thread. All we can do is to give some pointers which might help.

The main thing with swinging, is that it’s DANGEROUS. Propellers KILL, so the procedure you use must be designed to minimise exposure to risk as much as possible. But the risk can NOT be eliminated. The golden rule is the same as for anything else to do with flying - if in doubt, chicken out. There are basically 2 ways to do it - from the front or from the back.

Preference is front, but whichever you choose:
·    AVOID propping alone whenever possible. Whilst there may be nothing forbidding it, it is inherently unsafe. The last thing you want is your airplane without a pilot and with the throttle open too wide tooling across the airport!
·    ENSURE that the airplane is CHOCKED and BRAKED. The chocks are essential to saving the life of the ‘swinger’, as they stop the airplane chasing him!
·    AVOID using more than idle throttle settings while hand-propping. Even flooded airplanes will start eventually with the throttle at idle.
·    ENSURE good signals from cockpit to ground. Do not turn the prop unless you are both absolutely clear about what is happening. The 'swinger' is the boss! Your helper should keep their hands in plain sight of you before you go near the prop. Their instructions should include not touching ANYTHING while you are holding the prop!
·    ENSURE that you stand close enough to the prop. Stand close and pull your body away as you swing. This moves your whole body in the right direction. Standing away causes you to lean in and finish with your head low leaning into the prop!
·    AVOID wrapping your whole fingers around the blade. Wrap to the first knuckle only - you will need that one knuckle's worth of grip to do anything useful. Do not wrap your thumb around the blade at all. This is to allow the blade to fly out of your hands if the engine backfires.
·    ENSURE that no part of your body can ever enter the path of the prop blade at any time - not an arm, not a leg, NOTHING except the tips of your fingers - one knuckles worth.
·    AVOID turning the blade through to loosen the engine. If you must loosen a very cold engine, treat everything as though the mags are hot and the engine has fuel. Go through EXACTLY the same motions as when you really intend to start the airplane.
·    ENSURE that you stand about a foot back from the prop, with your left leg forward, and pull down with both hands. Don't pull hard - it's very unlikely you'll be able to raise enough momentum to get through more than one compression stroke, which is all you need anyhow. Pulling too hard will upset your balance.
·    ENSURE follow-through on your downward pull by letting your arms continue down and slightly to the right, to get your arms and the rest of your body headed away from the prop.
·    ENSURE that you call “mags off” after a failed start and get a response before moving the blade to the ready position.
·    ENSURE that you move quickly to the side and out of the plane of rotation when the engine starts, so that your helper can see you, and so that you do not accidentally walk into the prop.

Much of the procedure is reliant upon inter-person communication, strictly laid down so that each person knows what the other is doing. It DOES require trust, especially on the part of the ‘swinger’, but with that trust, knowledge and training you should succeed in the objective of minimising the risk.


FLY SAFE!

No comments:

Post a Comment