Hand Propping

Originally published October - November 1995

A few months ago I came across this conversation string on a national computer service. This particular string occurred during Aug-Sep of '94. The topic was a safety related issue having to do with aviation and I thought you might like to read some of the comments. <ed>

Hello

I am new to this Forum. I am a pilot active with EAA & IAC. I am looking for an article or information regarding the proper procedure for hand propping an airplane - or How Not to Hand Prop an airplane!!

I write the newsletter for our local chapter of IAC and would like to put something regarding this subject in an upcoming issue.

Thank you for your help.

Cheryl

Hi Cheryl,

Your question is a good one judging from all the replies.

I have handpropped a lot of equipment and the largest engine I propped regularly was a 260 HP Russian radial on a Wilga. It turns counterclockwise as well! I have never seen a book or instruction on it so maybe it's time someone wrote one! I have seen pictures of all kinds of setups. I have seen a human daisy chain to prop very large airplanes and the people sort of crack the whip to do it. I have seen bungee type slings that fit around a tip and turn the engine when stretched out. I heard a story about wrapping a sling around a good engine hub and then to the bad engine on twins and using the good engine's starter to prop the bad engine. I don't know if I believe this one but there it is. The strangest deal I saw was when I worked for a cargo hauler flying Convairs. We had a bad starter and the pilot windmilled the bad engine by racing down the runway at ONT until he lit the second engine. He idled it at the turn around for 45 minutes!

There are basically 2 ways to do it. From the front or back. I prefer the front because I am less likely to trip over a strut or tire if the airplane jumps. I also won't get run over by a strut or tire if the pilot is a _______. The most common mistake I see is not standing 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! The second mistake is wrapping (your fingers around) the blade as others have mentioned. From the front the pitch of the blade almost allows you to lay your hands flat on the blade but I usually wrap one knuckle. Third mistake is a cardinal sin and that is propping by yourself. Cool old J-3 pilots do this and it is absolutely unsafe and stupid. Don't do it. Either tied at the tail or chocked, it is unwise. The last thing you want is your airplane without a pilot with the throttle open too wide tooling across the airport!

I have rambled but here is the checklist.

1. The prop is ALWAYS hot (even when you think it's not).
2. No loose articles of clothing including pens and sunglasses and shirttails.
3. No loose gravel.
4. Good signals from cockpit to ground. a) mags off. b) make it hot. c) contact. Do not turn the prop unless you hear an appropriate response. You both must be absolutely clear about what is happening.
5. Prop from the front on solid ground.
6. Stand close and swing away. Don't lean in and don't be timid.
7. Turn the prop so that the compression cycle is coming on when blade you pull is up around 10 o'clock. After the pilot primes the engine flip a few blades with the mags *OFF* to draw the fuel into the cylinders. Remember the blade is hot even when it's not.
8. After a failed start call mags off and get a response before moving the blade to the ready position.
9. If the engine starts, move quickly to the side and behind the plane of blade rotation so the pilot can see you and not worry and so you do not accidentally walk into the prop.

-dan

Daniel,

There is no regulation banning handpropping an airplane by yourself. Nor would it be considered careless and reckless because a pilot's certificate is not required to do it.

I used to own an Aeronca Champ that I used to start by myself and it was perfectly safe. My procedure was as follows:

1. Airplane remains tied down.
2. Fuel valve is turned to the OFF position.
3. A Bungee cord is used to restrain the throttle in the closed position.
4. After the engine is stabilized in idle, I untie the airplane.
5. I crawl into the airplane, stomp on the brakes and pull the chocks using cords leading into the cockpit.
6. Turn fuel valve on, and release bungee restraining the throttle.

It works great, a no-sweat method.

-Barry

Your message about the strange methods of hand propping brought back an early memory. When I was a kid, I worked for Butler Aviation at ORD. This was in the very early '60s and in the days when DC-3s, Lodestars, and Learstars were king-of-the-hill in corporate aviation.

It was one of those very cold and windy winter mornings. None of our equipment could be started when I arrived for my shift at 0400. You'd have to ask the night shift why they didn't keep things running. We finally got a small heater cart started and were using that in turn to get others started and slowly working toward larger equipment. GPU carts were also dead.

During this, there was a corporate aircraft, a DC-3 if I remember correctly, that just HAD to leave. They couldn't wait for the larger heaters and/or GPUs. By that time we had one of the small tugs (baggage cart mover) running. The pilot gets this brilliant idea. He wants to know if we have a long piece of heave rope. We do. He says get it and also asks for one of the stands we use for cleaning windows on large aircraft. He climbs up and puts umpteen turns of rope around the spinner of one of the props. He then tells us to hook the other end of the rope to the tug. We then realize this guy thinks he has a big lawn mower.

Before that, we went through the exercise of manually moving the prop through quite a few revolutions to loosen things up. The tug was then used to pull the rope, slow at first and then a bit faster on each successive try. After more tries, the damn thing actually started. After running for awhile he was able to get enough power to get the other one started. Don't know what kind of damage this may have caused, but he was happy and was able to leave. This is a true story. I was the one driving the tug.

Jim...

Cheryl,

Daniel has given you some very good advice.

From my own experience hand-propping a Cherokee 180 that lost a starter 800 miles from the nearest mechanic (well southeast of Nassau) and with my T210 which has decided not to start on several cold winter mornings, here's what I ve learned.

1. Do NOT, repeat NOT wrap more than one knuckle around the prop blade. Be very careful not to wrap your thumb around the blade at all. This is to allow the blade to fly out of your hands if the engine backfires. BTW [by the way], you will need that one knuckle's worth of grip to do anything useful.
2. Be very sure that no part of your body is ever in the path of the prop blade at any time, EVER, EVER, EVER! Not an arm, not a leg, NOTHING except the tips of your fingers - one knuckles worth.
3. I stand about a foot back from the prop, with my left leg forward, this supposes a standard turning engine. Place both hands on the prop and pull downward. Here is the critical part, you should follow through on your downward pull by letting your arms continue down and slightly to the right. If done properly, your body motion should force you to take one to two steps backwards and away from the airplane. This is sort of like tennis or golf. Follow through is very important. It gets your arms and the rest of your body headed away from the prop. You want to encourage this motion away from the airplane. You should end up standing about 4 to 6 feet away from the engine and slightly to the right of your original position.
4. NEVER turn the blade through to loosen the engine up. If you must loosen the engine, for instance when it's very cold, treat everything as though the mags are hot and the engine has fuel. Go through EXACTLY the same motions you would use if you really intended to start the airplane. That way, when it does start someday by accident, you'll be safely away from the prop because you half expected the d**n thing to start anyway. On this point I disagree with Daniel. I have one and only one motion for turning a prop. That motion is the one I use for "propping" the airplane.
5. Don't pull hard when you prop the airplane. It's very unlikely you'll be able to get enough momentum to get through more than one compression stroke. Pulling too hard will upset your balance, possibly causing you to trip. Tripping in front of a freshly started airplane engine will scare you at the very least. One compression stroke is all you need anyhow. If the engine fires, it will have enough momentum to make the next compression stroke, and the next, and the next...
6. I am of two minds about having a helper. Personally, I'd rather tie the airplane down - all three tiedowns thank you - and then do everything myself. This prevents any accidents where the helper in the cockpit accidentally hits the starter while you're getting ready to hand-prop the engine. Legally, this is not possible, the regs (I believe) require someone (a pilot?) in the cockpit. If you must have someone in the cockpit, set everything up yourself, or have them do it if it's "their" airplane. Then make sure that they have their hands in plain sight held up on the glarescreen or on the overhead before you go near the prop. Their instructions should include not touching ANYTHING while you are holding the prop!
7. This one sounds sort of obvious, but...Never use more than idle throttle settings while handpropping unless the owner/pilot of the airplane is sitting in the cockpit with his/her feet on the brakes. Evern flooded airplanes will start eventually with the throttle at idle.
8. After the engine starts, back up at least twenty to thirty feet away from the engine. This is easy, when the engine starts it makes so much noise, you will do this naturally. Then walk behind the wing and get in the airplane.
9. Do this yourself. You want no one else near you while you are doing this. If you have passengers, leave them in the FBO or put them in the airplane with seatbelts on (so they won't get out to help you). This helps to avoid unwanted distractions.
10. Do not leave your chart bag beside the airplane, as this creates great comedy when the engine starts and your charts depart the airport at a great rate of speed.

Stu

Alan et al,

Pardon me but I really don't agree with the 'gist' of this thread. Here's my thoughts on the subject:

• Hand propping does not have to be a gut wrenching, sado-masochistic exercise in self destruction.
• I know of many people today, including an FAA inspector, who solo hand props HER own airplane, a J-3 cub.
• I know of no FAA reg that says you can't hand prop or that says you must have a qualified pilot at the controls. Many mechanics (not pilots) regularly hand prop and taxi airplanes.

Having said all this, I do agree that hand propping has caused many needless accidents and many injuries and fatalities. But, like anything else connected with flying, it can be done safely with proper instruction and practice.

This thread started by asking if there was a BOOK on hand propping. So far none has been identified. But in msg #649176 by Daniel , there is a really good checklist of "how to hand prop". This checklist, accompanied by instruction from a well experienced CFI or even a mechanic who has 'done it a few hundred times,' should be enough to keep you safe.

Generally, the rule is true. 'lf it has a starter, use it, don't hand prop.' But, if you want the thrill of flying a J-3 or an old Aeronca, learn how to hand prop. It's especially fun in a J-3 seaplane at Jack Brown's seaplane base in Winter Haven, FL. I got my seaplane rating there. It can also possibly get you home (safely) in a pinch.

Finally, I believe that hand propping is like spins - "You can't learn much about it by simply talking about it"

cheers.........leo

Hi Cheryl,

As someone who learned to fly on, and later owned airplanes which usually had to be swung, I'll try to give some thoughts on the matter. But first, the usual disclaimer... swinging is a manual skill, and should be learned by actually doing it under the guidance of an already qualified and experienced person - it can't be learned by reading an article/thread. All we can do is to give some pointers.

The main thing with swinging, is that its DANGEROUS. Propellers KILL, so the whole procedure is designed to minimize exposure to risk as much as possible. But the risk can NOT be *eliminated*. So the golden rule for swinging is the same as for anything else to do with flying - if in doubt, chicken out.

OK, now for what you need for swinging an airplane.

The first requirement is an *airplane* designed for swinging.

• To swing the prop, you need to get your arm up above your shoulder-level, and then bring down beneath your shoulder-level. So the airplane design should put the prop-spinner at about shoulder-level.
• If you lift your arm, and then swing it down and analyze the way your hand moves when doing this, you'll find that your hand swings not just downwards, but forwards as well. So, to give the prop-disk this angle as well, the airplane design should be a taildragger. Combine these two, and you see that swinging something like a PA28 or C150 is gonna be rather dangerous.

The second requirement, is an 'engine' designed for swinging.

• the engine should preferably be of a low compression, to allow you to EASILY move the prop with one hand. High compression engines CAN be swung, but require two hands, which makes the technique more dangerous.
• the propeller should be two-bladed, to allow a LARGE gap to follow your hand before the next propeller-blade, three-bladed props CAN be swung but are more likely to take your fingers off, as the gap between your fingers and the chopper is a lot smaller!
• one of the magnetos should be an impulse magneto, and the other mag should NOT. The impulse mag produces a spark with a wind-up spring to fire lots of energy at the right time when swinging the prop. (It helps to know WHICH mag is the impulse one - usually the left one, but worth checking!) And ideally, the magneto switching should be via separate switches, to allow you to positively control which mag is/is not selected.
• The engine rotation should be left-handed for swinging by the more-common non-southpaws. Yup - that means that most US planes aren't designed for swinging!

The third requirement is for TWO 'people' who know what they're doing.

• The 'swinger' is the boss, because they're the one putting their arms/life at risk here.
• the person in the cockpit MUST obey all instructions from the 'swinger', and MUST always be thinking about the swinger's safety.

All right, so assuming you've got the ideal combination of airplane/engine/people, or you're stuck with what you've got and you MUST get flying <g>...(That's computerese for a grin. -ed)

Do the usual preflight external and internal. But add to the list of things to do...ensure the airplane is CHOCKED as well as the brakes being on. The chocks are essential to saving the life of the swinger, as they stop the airplane chasing him! So the swinger should check that the chocks are wedged hard against the wheels properly to prevent the airplane running forward. (And also ensure that the chock-ropes are arranged properly, running from the INSIDE of the chocks.) The swinger can also check the brakes by trying to push the airplane backwards. It's also a good idea to check the area in front of the airplane for things that are going to be dangerous to a person there - but these would also be dangerous to the airplane, and so you'd check for this on your normal externals anyway, wouldn't you <G>?

The swinger starts by being WELL CLEAR of the prop, and in view of the cockpit, and calls the cockpit..."Fuel on, Brakes on, Throttle closed, Switches off'." The pilot checks these items carefully, and then repeats the call back, and then puts his/her hands OUTSIDE the cockpit. The basic rule here, is that if the pilot's hands are inside the cockpit, the swinger goes NOWHERE near the prop.

Depending on the engine, either the pilot or the swinger then primes the engine in its normal way. (If this was done by the pilot, he/she finishes by calling "ready to suck in", and puts his/her hands ouside the cockpit.) The swinger then calls "Sucking in", and approaches the prop with utter caution, and swings the prop over the required number of times for correct priming. For safety, and 'cause it's a good idea as a rehearsal to get the feel for this engine, use the same technique for moving the prop here as for the actual 'live' swing (see in a moment).

Once the sucking in is complete, the swinger leaves the prop at the 2 o'clock position for a left-handed engine, 10 o'clock for a right-handed engine, i.e. just before a compression. Then moves well away from the prop and into view of the pilot (a good opportunity to check the chocks/brakes again). Call "Throttle set, Contact" to the pilot. The pilot puts the throttle to the normal start position (1/4" open??), and selects the IMPULSE magneto on (and the other magneto OFF). Hands on throttle and stick and calls back to the swinger "Contact." (Notice that we do NOT use "Switches on" here - we use a very different phraseology from the opposite "Switches off" to avoid any confusion as to what the switches should be doing.)

OK, deep breath, here we go...Swinger double-checks clothing for anything which could be attractive to the propeller (tuck the white scarf away for now). Then moves to about 2 feet in front of the prop, but facing the SPINNER so that his/her body is at 45 to the prop-disc. For a right handed engine, your left hand reaches up to touch the prop blade, for a left-handed engine, your right hand. The hand does NOT *grip* the blade, it merely *rests* on the *front* of the blade (at a convenient distance from the tip). Do NOT curve your fingers over the back of the blade. Keep your fingers pretty straight, and use just the thicker flesh at the bottom of your fingertips to rest over the trailing edge of the blade. It's like *stroking* the blade downwards with your finger-tips.

Tuck your OTHER hand in the back of your belt to definitely keep it out of harm's way (to keep in reserve for the next attempt <g>?). Then you do two things at the same time...

• pull down with your hand - gently. You're NOT trying to wind up a rubber motor here - all you need is to get the engine JUST over the first compression, and let the compression and firing of the engine then take the prop out of your hand.
• and SWIVEL your body (away from the prop!) on the ball of the same foot as the hand that's doing the swinging. This actually helps you pull down with your hand, as it converts an arm action into an arm-and-body action. As you swivel out, the spare leg can extend so that you complete by having your hand low, your body facing completely away from the prop, and your other leg extended. Use your momentum at this point to step onto the extended leg, away from the prop, and then keep on walking well away from the prop - even if it hasn't gone bang. (It's this down-and-swivel action which you can practice during the sucking-in phase.)

If the engine has started, the pilot must remember to switch on the other magneto, and do all the other usual after start checks. The swinger keeps clear of the prop, and walks back into view of the cockpit (wing tip is a good place), ready to pull the chocks clear on signal from the cockpit.

If the engine doesn't start the first time, the swinger calls "Switches off" to the cockpit, to make if safe to go back to the prop and reposition it ready for another go. (Remember - if hands in the cockpit, go nowhere near the prop). Then "Contact" and deep breath time again.

As you can see, much of the procedure is inter-person communications, strictly laid down so BOTH people know what the other is doing. It DOES require trust, especially on the part of the swinger, but with trust, knowledge and training, maybe you can get an airplane flying where it should be.

Hope this helps a little,

-Richard

I just got the statistics from the Hand-proppers Quarterly.

100% of all glider pilots don't hand prop.

0.1 % of motor glider pilots hand prop and 0% handprop in flight.

100% of piston airplanes have props

95% of all piston pilots have never handpropped

5% have handpropped.

3% of this 5% are single armed pilots who state they will not handprop in the future but feel they know the procedures very well (now).

1.9% of this group claim to handprop daily and spend their time on computer bulletin boards and in airport cafes advising the 95% how to handprop.

0.1% of this group are no-armed pilots who have multiple handpropping experiences and claim they would handprop again if they could.

There is one statistically insignificant person who drives around different airports in a tow tug with a bungee cord offering to tug-prop cabin twins......

-dab

These notes on handpropping are the opinions of the authors and don't necessarily reflect the opinions of the Chapter. I, for one, am building an a/c that will require handpropping, hence my onginal interest in this subject. -ed

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