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Handcranking precautions

Sun Dec 26, 2010 10:44 pm

Have never handcranked an engine yet but do hang around a couple of types that have or had this type of system. I was reading about the possibility of kickback. Any tips from the experts about handcranking precautions in general or type specific.

Re: Handcranking precautions

Sun Dec 26, 2010 10:53 pm

Ober, care to chime in here.... :shock:

Re: Handcranking precautions

Sun Dec 26, 2010 11:21 pm

Sometimes, when the mags are timed differently, you can minimize the kickback risk by starting the engine on just one magneto - the one that is timed later. But anytime that you are around an aircraft engine with a live ignition system you are playing with fire. I've seen an old radial engine with no impulse couplings fire and start and run by just nudging the propeller. Every time you touch the propeller, expect it to start and conduct yourself accordingly.

Dan

Re: Handcranking precautions

Sun Dec 26, 2010 11:25 pm

Dan Jones wrote:Sometimes, when the mags are timed differently, you can minimize the kickback risk by starting the engine on just one magneto - the one that is timed later. But anytime that you are around an aircraft engine with a live ignition system you are playing with fire. I've seen an old radial engine with no impulse couplings fire and start and run by just nudging the propeller. Every time you touch the propeller, expect it to start and conduct yourself accordingly.

Dan


Dan, was it a stearman??? :D

Re: Handcranking precautions

Sun Dec 26, 2010 11:27 pm

N3Njeff wrote:
Dan Jones wrote:Sometimes, when the mags are timed differently, you can minimize the kickback risk by starting the engine on just one magneto - the one that is timed later. But anytime that you are around an aircraft engine with a live ignition system you are playing with fire. I've seen an old radial engine with no impulse couplings fire and start and run by just nudging the propeller. Every time you touch the propeller, expect it to start and conduct yourself accordingly.

Dan


Dan, was it a stearman??? :D



Hi Jeff,

Actually it was the Nanchang, but I have seen the Continental on the Stearman start by merely hitting the boost coil button. Didn't even touch the starter!

Dan

Re: Handcranking precautions

Sun Dec 26, 2010 11:36 pm

I might as well throw myself under the bus. We dont have a electrical system so we hand prop EVERY TIME or we dont fly. Every great once in a while we get a SIGNIFICANT kickback but if you have a good pull through, it wont happen. Now here are 2 videos of me at our 1st start of the year in 2009 and 2010. Now mind you, in FEB I almost died and was in the hospital for a month and lost a lot of upper body strengith so the MAY 2010 video took some work. Usually if things are well, she usually starts on the 2nd try. Mags are on Both.

http://www.youtube.com/watch?v=umDY2eqs ... re=related

http://www.youtube.com/watch?v=ruGYJlT9DSo

Re: Handcranking precautions

Sun Dec 26, 2010 11:42 pm

Dan Jones wrote:
N3Njeff wrote:
Dan Jones wrote:Sometimes, when the mags are timed differently, you can minimize the kickback risk by starting the engine on just one magneto - the one that is timed later. But anytime that you are around an aircraft engine with a live ignition system you are playing with fire. I've seen an old radial engine with no impulse couplings fire and start and run by just nudging the propeller. Every time you touch the propeller, expect it to start and conduct yourself accordingly.

Dan


Dan, was it a stearman??? :D



Hi Jeff,

Actually it was the Nanchang, but I have seen the Continental on the Stearman start by merely hitting the boost coil button. Didn't even touch the starter!

Dan


WOW a CJ-6.......they seem cranky every time I see one start.

Re: Handcranking precautions

Sun Dec 26, 2010 11:53 pm

The first time we started it by hand took us about half an hour (long enough for a crowd of fellow "airport bums" to form). After a while we figured out that the guy in the cockpit had to hold down the starter button to energize the boost coil even though the bottle was flat.

That's a good looking prop on your N3N. What is that?

Dan

Re: Handcranking precautions

Mon Dec 27, 2010 12:18 am

I guess I should clarify my initial statement. I am talking about using a crank on the side of the engine to start. The Harvard has this but I think that with the inertia starter there is no worry of a kickback. I have also seen a PT-19 use a handcrank for start. The biggest danger I saw in that case was the pilot start to taxi before the handcranker was clear of the aircraft. I have also seen a Hawker Hind stert up. It had a handcranker on each side of the engine.

My original question came from reading this on Wikipedia...

"Originally, a hand crank was used to start engines, but it was inconvenient, difficult, and dangerous to crank-start an engine. Even though cranks had an overrun mechanism, when the engine started, the crank could begin to spin along with the crankshaft and potentially strike the person cranking the engine. Additionally, care had to be taken to retard the spark in order to prevent backfiring; with an advanced spark setting, the engine could kick back (run in reverse), pulling the crank with it, because the overrun safety mechanism works in one direction only.

Although users were advised to cup their fingers under the crank and pull up, it felt natural for operators to grasp the handle with the fingers on one side, the thumb on the other. Even a simple backfire could result in a broken thumb; it was possible to end up with a broken wrist, or worse."


Looks like a very important reason to only have the impulse mag on for start in this scenario. Any other precautions. I suppose having good footing is important.

Re: Handcranking precautions

Mon Dec 27, 2010 12:49 am

It don't matter what type of crank, just remember at all times ............that sum bitch is out to kill you or someone else at all times period.

Re: Handcranking precautions

Mon Dec 27, 2010 1:06 am

For handProping, make certain to have the plane tied down, at least by the tail, and don't release it until after the start.
If no tiedowns, then chock it very well.

I have never handcranked an engine, but I think the same precautions are in order. Don't just rely on brakes or a non pilot.

A prop should be thought of as a big sword, just waiting until you stick your body in its arc.

Re: Handcranking precautions

Mon Dec 27, 2010 2:48 am

I've hand-cranked our Harvards a couple of times (intertia starter). If the direct drive starters have the same crank, there shouldn't be a worry about kick-back because of the way the crank fits into the starter shaft. It is unidirectional, so when you stop cranking, the hand-crank will slip freely out of the shaft.

However, make sure you start the engine the first time! Cranking the interia starter is a workout in and of itself. Make note that a small ammount of battery power is still required to engage the starter after cranking it.

Looks like a very important reason to only have the impulse mag on for start in this scenario. Any other precautions. I suppose having good footing is important.

The Harvard has a foot peg that pulls out of the LHS of the accessory compartment.

Drew

Re: Handcranking precautions

Mon Dec 27, 2010 5:40 am

I've hand cranked a few over the years and the biggest danger outside of working yourself into a heart attack, is falling off the wing or stumbling into the prop arc, depneing on what you are trying to start. Be secure in your footing when on a wing....ie clean up an oily wing beforehand, or in the case of being on the ground, face the crank rather than be parallel to the fuselage. By standing that direction, you don't get into as big of a rocking motion with the upper body. It takes a little more finesse that way and if you accidently yank the crank clear out of the socket, you aren't going to fall over due to loss of the crank as support.

Re: Handcranking precautions

Mon Dec 27, 2010 6:01 am

Hvd2Pilot wrote: Make note that a small ammount of battery power is still required to engage the starter after cranking it.
Drew


No, electricity is not required to use an inertia starter. The inertia starters also have a manual engage lever on them. After you get the inertia wheel wound up, you can remove the crank handle and pull the engage handle to rotate the crankshaft.

I've done this many times on Stearmans (N2S), BT-13's, AT-6's and a P-38 once.

Re: Handcranking precautions

Mon Dec 27, 2010 8:16 am

skymstr02 wrote:
Hvd2Pilot wrote: Make note that a small ammount of battery power is still required to engage the starter after cranking it.
Drew


No, electricity is not required to use an inertia starter. The inertia starters also have a manual engage lever on them. After you get the inertia wheel wound up, you can remove the crank handle and pull the engage handle to rotate the crankshaft.

I've done this many times on Stearmans (N2S), BT-13's, AT-6's and a P-38 once.



But the gent in the cockpit must still remember to turn the switch to 'ON', otherwise the fact that he signs your paycheck means as little as his apology and he can fetch the battery cart his own d**ned self, I'm going back inside where it's cool.
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