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Hand-propping

scsmith

Well Known Member
Rather than cause thread drift on Paul's thread about the broken starter, I figured I would start a new thread.

So, I've thought about hand-propping my IO-360 angle valve.

The problem I have is that the Whirl Wind 200RV prop is so light that it has no flywheel effect. Add to that, the trailing edge is pretty sharp, so it is hard to get much of a stroke on it anyway. But, I don't know, it would have to fire on the blade that you are pulling through to get it to go to the next blade anyway.

With a very low battery (the reason I would be hand propping) I can not be sure that the Light Speed EI would fire at TDC. If it fired 25 BTDC I think it would cut my fingertips off with the sharp trailing edge. On the rare occasion that I might need to do this, I think I would wish that the other mag had an impulse coupling.

I have hand-propped a O-470 with 2 bladed prop on a C-182. The only thing that made that difficult was that it was 15F outside, and it took a lot of pulls, priming some more every few pulls, to finally get enough fuel vapor in the cylinders to fire. By the time I got it started, I was stripped down to a Tee-shirt.
 
hand propping

I have hand propped four and six cyl Lycomings with Hoffman and MT two and three blade props, several were 10-1 compression. Also Navajo Chieftain several times. In the day many of the aerobatic airplanes didn't have starters.
 
Steve, I have hand propped lots of aircraft over my years of flying and thought I could prop about any single engine. Was at an airport 200 miles from home and had a dead battery and tried propping my RV7A 0-360 Catto Prop and it got me on a backfire. Took 30 stitches in left hand and broke my right. It's not worth it!!
 
Steve, if that occurs, charge the battery. How long would that take?

Then to prevent the change of it happening, install some sort of warning system if the master is left on.

Replace battery before it becomes marginal.

Consider this like get-home-itis. You have two options:

1) Do what is needed to avoid hand-propping even if it means a delay in getting somewhere, or

2) Risk serious injury or death.
 
I'm pretty sure that hand-propping only gets you one cylinder to fire in any event. And you could wear cheap work gloves when propping it.

Just be careful.

Dave
 
Yeah....I think hand-propping your set-up might be beyond my comfort level Steve. I am happy giving a 360 a go if it has Mags, a two-blade prop, and is a tail-dragger (and the -6 sits low enough as a tail dragger that it was about on the Go/No Go line for me). I'd have hand propped the Val when it had Mags, but with the P-Mags, I'd have to think about it. In our case last weekend, it wasn't a matter of charging the battery or jumping - we had no starter, so we were lucky that it was a simple engine/prop combo.

And just to put it all in perspective, I grew up flying Cubs - hand propping was the first thing I learned, and it is almost second nature. Still scares me if if I don't have the right conditions!

Paul
 
We have the same set-up, only our angle valve is the dual mag kind. I defintiely would not want to hand prop it.

As a safety note. It is very easy to hand prop, even accidently. To set the scene, our RV-8 was in the hangar, top cowl off, throttle idle, mixtured cut-off (as it was shutdown), hangar door closed and spinner 10 inches awayfrom the inside of the door. My partner was working on our mag, one side quit firing and he simply moved the prop. Bang, the engine starts immediately and runs for about 2 seconds. Needless to say, scared the #$%^ out of him. Turns out he had left one of the mag switches on. The only thing that saved him was the plane was chocked (he was between the prop and hangar door) and he always treats a prop like the mag is hot.
 
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It depends on what electric ignition system you have, but on my Lightspeed, I'm pretty sure it fires at TDC at start-up. Doesn't have any trouble starting my engine. I've propped an O-360, but not with 10:1 compression ratio. That might be a little tough. The O-470 carbed engine is a low compression engine and not as hard to hand prop especially with a long prop.
 
Interesting all the issues with props, just last night I decided to mount my Catto Tri-Prop just to turn the prop on my brand new 1 year old IO 360 Mattituck Engine to push some lubricant around, 4 plugs are out having moisture plugs for storage. On my second pull off the compression stroke the next blade came around and hit me right in the head knocking me to the ground, no blood just a nasty dent on the head. Today I pulled all the plugs, learned my lesson... Still not sure why my wife came out to the garage laughing when she saw me on the ground...
 
I don't have hard facts, but my guess is most contemplate hand propping after leaving the master on over night, not mechanical failure. In most of our airplanes, if your battery is dead, you have no alt. current, no charge, no electrical. In most of our airplanes, no electrical means you are not even going to consider going anywhere unless it is a true emergency.
I have propped a few 0320/0360's, usually after enough charge was put on the battery to get the alt. alive. It is not my favorite thing to do, but I wouldn't say it is necessarily "difficult".
I propped my old L3 without any electrical system hundreds of times, for many years, cause that is what you do. Of course, it was only 65hp, which is just enough to kill you.
A lot of thought goes into it before I ever consider a hand prop. It is very dangerous and the engine and prop hold no prejudice or forgiveness.
 
Hand Propping

''Catto Prop and it got me on a backfire''

''decided to mount my Catto Tri-Prop ''

Well there must be something with the Catto Prop...??( Just kidding ):rolleyes:

I've got a Catto 3 bladded on my RV-4 and on May 15th of this year, I hand propped it so I could get the battery recharged ( after extensive used of the battery ) and with 2 Lightspeed ignition on my -4, it has always started on the first or second swing but not this time..

I tried numerous time and it just wouldn't start so after a last try where the engine almost caught, I decided to give it one more try and as I was at the point where I would normally release my grip on the prop,it kicked back....

With my left arm fully extended and with the strain of the kick back, my left bicep couldn't take the load and ripped right of the bone....

I don't need to tell that it hurt a tidy bit...:eek: and I ended up with an arm that looked like it belonged to Popeye...

With emergency surgery and 6 months of extensive physiotherapy, I'm finally going back to work in a couple weeks...

No more hand propping for this puppy, I now carry a battery booster in the aircraft and if it doesn't start...Marriott will be glad to have my business if I can't find a boost on the airport....

Be careful out there folks..

Bruno
 
I have hand-propped a lot of different types of planes over the last 25+ years. Some types are certainly easier than others. I don't think it matters if the plane has a lightweght prop with little flywheel effect, as you will almost never get a healthy (good compression) engine past the compression stroke of a single cylinder (two if your lucky) by hand-propping. As long as the ignition fires at TDC the engine hopefully will start.

I think the often overlooked thing about hand-propping, is if/when you get the engine started you are about to take-off with basicly a dead battery (the most likely reason you hand-propped in the first place) So now if you take-off and have an Alternator failure you have VERY LITTLE or NO Back-up electrical power for things you may really need to complete you flight.

Be Careful out there Folks
 
Lots of good experiences/lessons here

Ron has the right idea. Dead battery from leaving master on.

So, I put the charger on it, and after an hour, the battery was partly charged, but not enough to crank the engine. So, we are still waiting around.
This is when the thought comes, to hand-prop or not.

The LIght Speed will fire at TDC when hand propping PROVIDED there is at least 6 volts to run the controller. If the voltage drops below 6 volts, I'm pretty sure it reverts back to the static timing, 25 BTDC. So that is the risk.

Having a very light-weight prop was the deciding factor for me - there is just not enough inertia to reliably get it to follow through, so you have to be that much more positive in your 'connection' to the prop, which increases the risk of bad things happening, among the experiences cited here.

So my decision was to wait another 2 hrs ( I have a small charger) and then it started. My wife was not very happy about the 3 hr delay, but I was happy to still have all my fingers, no dent in my forehead, and my biceps muscles still attached to bone.

Funny, a wood prop on a C-85 never seemed like a problem, but a 72" carbon prop on an IO-360 just isn't enough.


Steve, if that occurs, charge the battery. How long would that take?

Then to prevent the change of it happening, install some sort of warning system if the master is left on.

Replace battery before it becomes marginal.

Consider this like get-home-itis. You have two options:

1) Do what is needed to avoid hand-propping even if it means a delay in getting somewhere, or

2) Risk serious injury or death.
 
Good to hear a positive outcome Steve.

I have had enough delays traveling commercial aircraft and my 6A that I accept delays. You can't let a trivial three hour delay lead you down the decision tree to a bad outcome.

Monday I was flying United from Michigan to COS via O'hare. A delay leaving Michigan resulted in me having to overnight in Chicago. Such is life. It did give me the opportunity to help two Russians get to a gate in another concourse, eat at Johnny Rockets (not up to par) and try a White Castle burger for the first time (probably the last time).

It was also the first time I stepped outside the O'hare airport terminal.

Lots of good discussion from people who can competently hand prop when the situation is right...and those who had less positive outcomes.
 
I think the often overlooked thing about hand-propping, is if/when you get the engine started you are about to take-off with basicly a dead battery (the most likely reason you hand-propped in the first place) So now if you take-off and have an Alternator failure you have VERY LITTLE or NO Back-up electrical power for things you may really need to complete you flight.

And to add to this, you are seriously taxing the ability of your alternator at this point, it will be outputting maximum current until the battery is recharged. Your poor little alternator is not designed for charging a dead battery, alternator distress in high, failure is very possible (or at least a shorted life).
 
Ultimately you have to get home

You can't just say trying to get home is a bad thing and I will just sit here. You can get into some pretty helpless life threatening settings with these airplanes so it is good to know what options you have, what you have to do to make them work and start implementing the best option as soon as practical. Several times I had to hand prop out Archer over 22 years of ownership and I hand proped my friend's 182 coming back from a trip in Mexico once. It scared the H___ out of me every time but worrying about such things as strain on the alternator was so far down the list of concerns that it is not an issue. I agree that it is one of the least desirable options but if I were stuck in the middle of nowhere with no communication, food or water I think I would give it a shot. I try to pull it through the compression stroke with finger pressure on the blade surface but I know that if it doesn't work I am going to have to "Grab" the prop. My ignition system is a non-bush kit LASAR and it will not start with hand proping but it will air start from a fast windmill (yes I have had to do it). I can envision an emergency attempt at a catapult launch if the conditions made it possible - OK maybe that went too far - but I would consider every option to complete the mission - to survive and get home. The last time it happened to me I had to order a new battery from Aircraft Spruce and wait for it to arrive before I could start up and fly home.

Bob Axsom
 
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Don't cook the alternator

And to add to this, you are seriously taxing the ability of your alternator at this point, it will be outputting maximum current until the battery is recharged. Your poor little alternator is not designed for charging a dead battery, alternator distress in high, failure is very possible (or at least a shorted life).

Very true. I ran down the battery trying to start a primerless engine on a cold morning (operator error) then jumped the dead battery with cables from the car. The little 35a Vans alternator was putting out 49a recharging the flat battery.....the alternator was dead within the hour.

Lesson learned. If the battery is flat, bring it back with a charger, not the alternator.
 
Over almost 35 years I've had the "opportunity" to prop Broussards, T-28, tri-motor, all the way down to A-50, O145, and a 1/2 volks. I've always been careful, I've always been scared. You guys make me even more scared. That's good. I always feel safer with a tied plane and nobody inside. That way I KNOW where the mags and throttle are. Most of the 7AC guys don't even get out of the plane. They reach out the door and give the little 65 a flip. There's little margin for error in hand-propping technique. You have to stand right, reach right, and have all your body parts headed in the right direction. This gives you your best odds of keeping all your body parts attached and aligned. Higher compressions and light props make it very tricky and I wouldn't screw around at all with elctronic ignitions. Its one of the reasons I still like magnetos. I "know" what a mag wants to do and where its going to do it, provided it has good P-leads.
P.S. Please don't try it with a 421 or a Duke, and don't do it on ice or snow.
 
Dead Battery

Sam

''If the battery is flat, bring it back with a charger, not the alternator.''
-------------------------
That's one of the reason why I carry this little battery booster,It will take a battery down from let's say 6 volts and boost it up 11 volts in about 10 mins..
At 11 volts, the engine will start every time and my body parts will be all where they are supposed to be..

I've hand propped just about every pistons airplanes before from little Cubs to Single Otters but not anymore unless the strip is on fire and I need to get out of there..
Nothing is urgent enough that it requires hurting yourself, flying at our level is for fun and #2 can wait for me to get home...

Just my $0.02

Bruno
 
Somebody suggested installing a warning system to let you know you left the master on... you've got one. When shutting down, just don't turn of the strobe switch. It's hard to walk away from a plane with the strobes flashing. (learned from the Jacksonville Sheriff's Dept. Aviation Division.) Ben
 
so what IS the right way?

seems like a lot of guys are still getting injured.
Where do you go to learn the proper way?......all this talk and experience and it sounds like nobody knows if there is one, or what the correct technique might be!!!

I've only propped a 85-hp continental, taught by my dad...who learned from some J-3 guys ( of course they ususally did it from behind the prop, often standing on a float!) It was the typical swing your foot, pull-thru, and move away all in one fluid motion.

at our local club, one guy shared a technique where once set, primed and the prop positioned, with the switch on, one could s-l-o-w-l-y move the prop on a 172 while standing behind, with one or 2 fingers only, until it fired...without all the risk associated with using a lot of force while balancing on one foot etc.

Can we agree on.... or learn the best method, and save some hands/scalps?
 
Two ways, many variables

There are two basic ways that most of us are taught, but many variables can influence the ease, safety, and success of trying to hand-prop an airplane.

The 'normal' way for land planes is facing the airplane. the other way is from behind the prop, and is normally done on float planes (kinda hard to stand in front of the plane;) and this is mostly done with smaller engines.

The problem is, the variables are things like the height of the prop relative to your hands, position of the compression stroke, how high a compression ratio, how heavy a prop, how many blades, and probably other factors.

Some people who were previously very experienced and successful with hand-propping have recounted some special circumstances here in this thread that led to injury, even though they are using the nominally 'standard' method.

So, agreeing on a standard method isn't going to prevent injuries, and why some here have said they just won't do it. Those that do, recognize how to adapt the standard method to the special circumstances, or at least recognize the need to, and decide for themselves on the risk/benefit trade.

Another complicating factor -- just to add to the discussion: Lets say it is a Lycoming with Bendix F.I. and has already been run today - which means it is basically flooded. Using the starter, I go WOT, full lean, and it cranks for about 5-7 seconds before it fires, then I add mixture and retard throttle to keep it running. So......given that situation, is it even POSSIBLE to get it to start on a hand-prop? If it won't fire for 5 seconds of WOT cranking, how are you going to get it to start on a hand-pull? I guess I would go WOT, switch cold, and prop it through a bunch of times to try to flush the flooded cylinders, then I would prime and try to start as if cold (idle throttle, rich mixture). I don't know if that would work?
 
The FAA version

Introduction to Flight Training

An engine should not be hand propped unless two people, both familiar with the airplane and hand propping techniques, are available to perform the procedure. The person pulling the propeller blades through directs all activity and is in charge of the procedure. The other person, thoroughly familiar with the controls, must be seated in the airplane with the brakes set. As an additional precaution, chocks may be placed in front of the main wheels. If this is not feasible, the airplane?s tail may be securely tied. Never allow a person unfamiliar with the controls to occupy the pilot?s seat when hand propping. The procedure should never be attempted alone.

When hand propping is necessary, the ground surface near the propeller should be stable and free of debris. Unless a firm footing is available, consider relocating the airplane. Loose gravel, wet grass, mud, oil, ice, or snow might cause the person pulling the propeller through to slip into the rotating blades as the engine starts.

Both participants should discuss the procedure and agree on voice commands and expected action. To begin the procedure, the fuel system and engine controls (tank selector, primer, pump, throttle, and mixture) are set for a normal start. The ignition/ magneto switch should be checked to be sure that it is OFF. Then the descending propeller blade should be rotated so that it assumes a position slightly above the horizontal. The person doing the hand propping should face the descending blade squarely and stand slightly less than one arm?s length from the blade. If a stance too far away were assumed, it would be necessary to lean forward in an unbalanced condition to reach the blade. This may cause the person to fall forward into the rotating blades when the engine starts.

The procedure and commands for hand propping are:
Person out front says, ?GAS ON, SWITCH OFF, THROTTLE CLOSED, BRAKES SET.?

Pilot seat occupant, after making sure the fuel is ON, mixture is RICH, ignition/magneto switch is OFF, throttle is CLOSED, and brakes SET, says, ?GAS ON, SWITCH OFF, THROTTLE CLOSED, BRAKES SET.?
Person out front, after pulling the propeller through to prime the engine says, ?BRAKES AND CONTACT.?

Pilot seat occupant checks the brakes SET and turns the ignition switch ON, then says, ?BRAKES AND CONTACT.?

The propeller is swung by forcing the blade downward rapidly, pushing with the palms of both hands. If the blade is gripped tightly with the fingers, the person?s body may be drawn into the propeller blades should the engine misfire and rotate momentarily in the opposite direction. As the blade is pushed down, the person should step backward, away from the propeller. If the engine does not start, the propeller should not be repositioned for another attempt until it is certain the ignition/magneto switch is turned OFF.
The words CONTACT (mags ON) and SWITCH OFF (mags OFF) are used because they are significantly different from each other. Under noisy conditions or high winds, the words CONTACT and SWITCH OFF are less likely to be misunderstood than SWITCH ON and SWITCH OFF.

When removing the wheel chocks after the engine starts, it is essential that the pilot remember that the propeller is almost invisible. Incredible as it may seem, serious injuries and fatalities occur when people who have just started an engine walk or reach into the propeller arc to remove the chocks. Before the chocks are removed, the throttle should be set to idle and the chocks approached from the rear of the propeller. Never approach the chocks from the front or the side.

The procedures for hand propping should always be in accordance with the manufacturer?s recommendations and checklist. Special starting procedures are used when the engine is already warm, very cold, or when flooded or vapor locked. There will also be a different starting procedure when an external power source is used.
 
I used to hand prop a Luscombe 8a (65hp) I had a 1/2 share in back in England, had to, no electrics. One winter (cold and damp) I swung that thing forever, and it would not start, turned out to be a mag fault. But I kept the people in the tower at Rochester amused for about 30 minutes.:)

To add to N51p good , We also used to use 'key out' the person in the cabin would then pull the key out of the mag/ignition switch hold the key up for the hand starter to see and then put it on top of the dash.
 
Weirder still

I've propped a Chieftain, Mooney, Stearmen (plural of Stearman?)
lots of small stuff J-3, champ, luscombe etc. and my Whirlwind propped RV-8. Every time I do it, it is serious business...that thing will kill you if you aren't really careful.

The RV-8 is the scariest so far. There's ZERO inertia with that lightweight Whirlwind. I basically prime, pull a couple of blades (cold mags), position the prop just at the onset of a compression stroke, and then SLOWLY pull it through. When the impulse coupling releases, it's running, so be out of the way.

Who on the list has hand propped a jet?

We're in the Hawker, down on the island of Bonaire, the wind is howling 40 knots right up the tail pipe. If we engage the starter with that much reverse rotation it will shear the starter/generator shaft instantly. There's no tug, towbar, nor anyone to help turn the Hawker (27,000 pounds) around into the wind by hand. Captain says to eager young co-pilot "Go out and climb up on the wing, use your hands to stop the reverse rotation of the fan and as soon as I engage the starter, wait until N1 starts spinning the correct direction, let go and jump down"...easy right? It worked great. The engine started.

Happily, I'm no longer young, eager or a co-pilot.

Be careful and remember..."If you have time to spare, go by air"
 
Tim Wins?

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Years ago I was in my yard and heard a rapidly increasing engine noise .... possibly to near full throttle. It lasted just a few seconds before there was a thud and the engine noise stopped.

The pilot of a certified plane had hand propped it with his likely non-pilot wife at the controls. The planes motion was stopped by a hangar. The wife received non-trivial upper extremity injuries and the pilot was lucky he was not killed.

I do not know if the plane was totaled but it may have been.

I do not recall more specifics but would not be surprised if this was brought on by a need to go somewhere and not taking the time to fix the underlying mechanical/electrical problem.
 
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