Does anybody know what is the most effective way of hand propping a Cessna 172N, with a passenger who is not mechanically inclined.

So you need to give them the most easy to follow and simple instructions. Like after pulling the hand brake, and priming and opening the throttle 1/4 inch what do you tell them to do?

I would push the throttle gently in after I'd hear the engine coughing to power when hand propped, while keeping my feet on the brakes, till engine's smooth revving and maintaining power.

But to a person that has no familiarity with the noise of the engine and does not know what to expect, what should I say.

Edit I thought I should elaborate a bit to shed some light on what happened.

We had come back from a half a day of hiking around the hills of Santa Ynez in the afternoon with my hiker friend. After trying to crank the ignition a couple of times, it just moaned jerking half way through a hesitant arc.

We looked around for something to use as chocks, found two rocks like 8-10inched and kind of heavy and pushed them to a locking position in front of the tires.

I set the throttle; told him not to touch it before I jump back after cranking and wave him all clear. Then he pushes the throttle by half an inch while pushing the breaks. We brought the engine back to life after a few tries.

After I felt we have a enough of prop rotation inertia I got on to the right seat and brought the RPM down. He got out and removed the rocks. Got back in and we flew back to Van Nuys.

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    $\begingroup$ You should say you aren't going flying that day and get the starter fixed. $\endgroup$
    – GdD
    Commented Nov 18, 2019 at 8:56
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    $\begingroup$ I'm pretty sure hand propping is illegal if the other person in the plane is not also a fully-qualified pilot in my country (Germany). You definitely want to check legal requirements as well. $\endgroup$
    – Nijin22
    Commented Nov 18, 2019 at 14:00
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    $\begingroup$ To add to legal requirements, all original equipment should be working, or deactivated/disconnected and placarded inop. IDK if you can legally do this to a starter, but assuming you can, get a mechanic to double check the starter isn't engaged or loose, or remove it completely - I've seen a 182 nearly catch fire inflight when a partially bad starter began shredding gears. All that said, do what you want, but if your untrained passenger screws up and the plane goes into a building and/or hurts people, you are gonna have to explain it to the FAA, the insurance company, and maybe a civil court. $\endgroup$
    – nexus_2006
    Commented Nov 18, 2019 at 16:47
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    $\begingroup$ The person at the controls MUST know how to handle potential engine starting emergencies such as an engine fire. They MUST know how to shut off fuel and batteries. $\endgroup$ Commented Nov 18, 2019 at 18:33
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    $\begingroup$ Was that "non-intuned" or "non-entombed"? I don't think "intuned" is a real word, but I suspect one or more of the parties involved will soon be "entombed". $\endgroup$ Commented Nov 19, 2019 at 1:35

5 Answers 5


That is crazy. DON'T just rely on an person who's new to airplanes and only training is 5 minutes of showing them what to do, who may or may not react correctly when it springs to life, as the only thing preventing the plane from heading off somewhere while you try to dive clear. Don't. Do. It.

Tie the tail. To something. Anything. Use the passenger and show them what to do and give them a careful briefing, but tie the tail down anyway. You don't know how the passenger is going to react if things go off kilter. And if tying the tail is simply not an option, and you have no choice because you have to leave because zombies are approaching, at least point the airplane toward some obstacle just beyond the normal turning radius, like a wire fence, for it to run into when it takes off with your passenger confused and frightened because they pushed the throttle in too much and let off the brakes when the thing jerked forward on them, with you diving for your life.

Once it's running at idle and everything is kosher, set the parking brake and you can walk back to untie it with your passenger ready to switch the ignition off if it starts to roll away.

And make sure to use the correct terminology with your assistant. Don't say "switch on/switch off". It's "Switch off" for ignition off, and "Contact" for ignition on (it's old fashioned sounding, but it works).

I have been personally burned by a guy who did things the usual way, when I said "switch off", then repeated "switch off" to make sure he heard it. He thought I'd said "Switch off" then "Switch on" when I'd just said switch off twice. I neglected to brief him on the use of the word "contact" so it was my fault in the end. Anyway, I got a nice noisy surprise when I turned the prop over thinking ignition was off.

Hand propping is quite a dangerous operation, especially on tri-gear airplanes where you have to lean forward to do it. I trust you yourself have been properly trained, and know things like not to hook your fingers over the blade so you don't get pulled into it if it kicks back, that sort of thing.

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    $\begingroup$ This is good advice, I would point out I haven't seen a Cessna with a working parking brake in 15 years of flying. $\endgroup$
    – GdD
    Commented Nov 18, 2019 at 12:26
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    $\begingroup$ +1 for leading out of the gate with that is crazy. I'd give a second +1 if I could for the zombies. $\endgroup$
    – TypeIA
    Commented Nov 18, 2019 at 13:16
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    $\begingroup$ Yep it's one of those topics where bluntness is necessary, although it's not meant to be insulting or demeaning. I have acquaintences today that own a, you guessed it, an Aeronca Champ with an A-65 engine in a partnership, and they start it routinely with nobody aboard and using only little metal chocks. I've told them it's crazy also. $\endgroup$
    – John K
    Commented Nov 18, 2019 at 13:22
  • $\begingroup$ @John K How do you intend to pull the blade without hooking your fingers over it? $\endgroup$
    – Pete Danes
    Commented Nov 19, 2019 at 21:31
  • $\begingroup$ You place just the tips of your fingers over the edge of the blade, about the middle area of your fingerprint, not at the joint where you would normally do it by instinct. The little notch in the finger joint makes a great hook and increases the ability of the blade to pull you in if it kicks back. $\endgroup$
    – John K
    Commented Nov 19, 2019 at 21:38

I’ll second John K’s answer. Do not attempt to hand prop an airplane without receiving professional instruction on how to do it safely. It is a real easy way to get seriously injured or killed, as this idiot almost found out.

It should also involve two competently trained people, one to do the hand propping, and the other at the controls of the airplane during the process to control fuel, ignition and throttle throughout.

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    $\begingroup$ Back in the 70s, at a little airport north of Toronto, Ontario, a guy was hand starting his Champ unsecured and overprimed it. He switched off, opened the throttle wide, and flipped it through backwards to clear it out, then switched on the mags and gave it a flip... and off it went, taking off and doing 2 circles of the airport before crashing, amazingly only a couple hundred feet from where it started and cartwheeling into a ball without any other damage or injuries, other than the picnic table. It got a little 2 inch column item in the Toronto Star the next day. $\endgroup$
    – John K
    Commented Nov 18, 2019 at 4:48
  • $\begingroup$ @JohnK This sounds hilarious. Any links to archive articles? $\endgroup$
    – Cloud
    Commented Nov 18, 2019 at 10:29
  • $\begingroup$ No I tried to find it on the Star web site once but no luck. The airport was called King City Airport, so see what you can find. The Champ will fly unpiloted because the pilot sits pretty much exactly on the C of G so there is no trim change. This one went on a climbing left turn that turned into the beginnings of a descending left spiral. There was a Champ in Pennsylvania I believe that did the same thing and flew straight for quite some distance before crashing itself. $\endgroup$
    – John K
    Commented Nov 18, 2019 at 13:08
  • $\begingroup$ The video was disabled on Youtube. $\endgroup$
    – nomen
    Commented Nov 18, 2019 at 18:22
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    $\begingroup$ @nomen No it wasn't, it's disabled from playing while embedded in websites other than YouTube. You can see it by clicking the "Watch this video on YouTube" link that shows when you try to play the video. $\endgroup$
    – rclocher3
    Commented Nov 18, 2019 at 19:01

If the person operating the throttle has to react within a fraction of a second to a changing sound that's unfamiliar to them, they're doomed. So play them a few videos of good and bad starts to make the sounds familiar. Tell them what to do in reaction to the changes. Quiz them a few times to ensure they understand.

This might take ten minutes, but then they'll be happy to have mastered a new skill, and you'll have gained a second pair of ears listening carefully during the flight itself.

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    $\begingroup$ I wish I had the luxury of having data reception. It happened to me last year in Santa Ynez. We had to look for boulders to use as chucks, it was kind of a experience for both of us. $\endgroup$
    – kamran
    Commented Nov 17, 2019 at 23:55
  • $\begingroup$ ... and if they're overwhelmed by this amount of instruction, you can't count on them to do anything critical. In fact you probably shouldn't count on someone reacting properly the first time after having only watched videos and talked for a few minutes. IDK if you've ever played World of Warcraft or other online MMORPG, but the first few attempts at something often have spectacular failures of players to react to something they had watched a video about. If reacting properly is safety-critical, you can't put that in the hands of someone totally inexperienced even if they seem interested $\endgroup$ Commented Nov 19, 2019 at 20:24
  • $\begingroup$ Yep. That's why I wrote "Quiz them a few times to ensure they understand!" $\endgroup$ Commented Nov 19, 2019 at 22:49

A c172 is hard to prop safely, most trigear aircraft are. Do not let any non-pilot get near any prop! In an emergency, say your stranded on a Baja desert strip with a dead battery, tie down the tail, work all controls yourself,ie switch's,mixtures,throtles etc. If I think well of my passenger I might place his hand on the throttle to pull back on my signal,and prop it yourself, if you've been trained, If not? activate your ELT and pray for a helicopter.


Most important: tell your untrained passenger to keep the brakes applied no matter what. Then try to push the plane to make sure he's really on the brakes.

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    $\begingroup$ You can't verify that he's still on the brakes while you're hand propping. Use wheel chocks or tie down the tail. $\endgroup$ Commented Nov 19, 2019 at 17:12
  • $\begingroup$ The question was what should you tell the passenger, not what else you should do. $\endgroup$
    – stretch
    Commented Jun 12, 2020 at 11:37

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