Chocks for hand-propping

dbahn

dbahn

Pattern Altitude
Joined
Aug 28, 2007
Messages
1,562
Location
Vermont
Display Name
Display name:
Dave Bahnson
This probably doesn't apply for most people, but for those who fly hand-propped aircraft I thought I'd share this system of chocks I made years ago. They allow you to prop the plane and get into it with the chocks in place then safely remove them once settled. They're easily made with plywood and epoxied fiberglass and can be stored easily in a small space.


It's a variant of the stitch and glue method of building kayak that I reference in the kayak thread.
 
Really cool!

The only time I've ever had to really focus when hand propping is on tarmac where the surface is level or downhill - then it gets exciting! These would definitely make it much easier! Alas, the only J3 I fly now has a starter.
 
Cool! You should contact Sporty's about marketing these. (After all, if they can put a loop in a two foot rope, call it a chock, and sell it for forty bucks....)
 
Very similar to the ones I use with the T-Craft I flay as far as the rope tether and pulling it in once I am in the cockpit. I love your design for storing the one inside the other.

Brian
CFIIG/ASEL.
 
Those are super cool chocks, but based on personal experience, I don't believe that chocks are a good idea for hand propping. It seems they were sufficient in this situation, but the fact that they're so easily removed from behind, and the Cub doesn't move when they're removed, suggests that they also weren't necessary in this situation.
 
Lindberg said:
Those are super cool chocks, but based on personal experience, I don't believe that chocks are a good idea for hand propping. It seems they were sufficient in this situation, but the fact that they're so easily removed from behind, and the Cub doesn't move when they're removed, suggests that they also weren't necessary in this situation.
Click to expand...
1. Why aren’t they a good idea?
2. Maybe they aren’t necessary on grass but they are definitely necessary on a hard surface. Regardless, without them, whether on grass or hard surface, opens the door to careless and reckless if something were to go amiss.
 
Lindberg said:
Those are super cool chocks, but based on personal experience, I don't believe that chocks are a good idea for hand propping. It seems they were sufficient in this situation, but the fact that they're so easily removed from behind, and the Cub doesn't move when they're removed, suggests that they also weren't necessary in this situation.
Click to expand...

I don't understand your objection. Why specifically don't you believe that chocks are a good idea for hand propping? Sure, they weren't necessary in THIS situation - that's not the point. I have hand-propped solo many times with no chocks. Every time I am aware that this may be the day that it gets away from me. It's kind of like the seat belt argument. You wear it every single time, just in case something happens.

I LOVE this chock setup.
 
Last edited:
Greg Bockelman said:
1. Why aren’t they a good idea?
2. Maybe they aren’t necessary on grass but they are definitely necessary on a hard surface. Regardless, without them, whether on grass or hard surface, opens the door to careless and reckless if something were to go amiss.
Click to expand...
I've seen planes jump chocks when started. So I much prefer to tie the tail if there's no one to hold the brakes.
 
Lindberg said:
I've seen planes jump chocks when started. So I much prefer to tie the tail if there's no one to hold the brakes.
Click to expand...
Ok, that is the SAFEST way to handle the situation and if you have a long enough rope, you can tie the rope in such a way that you can release the knot from the cockpit. But I have not seen a tail tie down rope long enough to do that so you would still have to leave the cockpit to untie it.

I take the first part of this post back. The absolute safest way to prop an airplane is to have a qualified person at the controls while someone else does the propping.
 
Greg Bockelman said:
Ok, that is the SAFEST way to handle the situation and if you have a long enough rope, you can tie the rope in such a way that you can release the knot from the cockpit. But I have not seen a tail tie down rope long enough to do that so you would still have to leave the cockpit to untie it.
Click to expand...
Install a Glider/Banner tow hook. Take an unused tiedown rope, tie a small loop in it, drop it in the hook and close it. Then start the engine, get in the cockpit, and pull the release for the hook.

I flew Pete Bowers' original Fly Baby for seven years. Used the tail hook for nearly every start. Accidentally started the engine at full throttle once, and it held well enough to let me run around the wingtip and throttle back.

http://www.bowersflybaby.com/tech/tailhook.html

Homebuilts can use home-made versions, but there are several companies selling commercial/STC'd versions of these. Schweizer itself used to sell these, dunno if they are still available.

Ron Wanttaja
 
Lindberg said:
I've seen planes jump chocks when started. So I much prefer to tie the tail if there's no one to hold the brakes.
Click to expand...

Just to be clear, I use a tail tie-down rope most of the time. It's held by the center post of my hangar door and protects against a runaway if for some reason the RPMs are high on start up. But after it starts I still need to slow it to idle and get into the plane, so the chocks can be used in that phase (although frankly I just walk it to the grass and climb in without using the chocks most of the times).
 
Chocks are a necessity for me. No parking brake.
I made my own chocks by cutting a 4x4 diagonally. They work fine.
I tried the long rope, self removal thing. Didn't work. Once the wheels were up against the chocks the chocks have to be pulled forward to release them. sigh...
I was thinking about installing a parking brake, then realized I would never trust it. It would only have to slip once while I'm standing in front of it to spoil the rest of my (short) life.
Chocks it is.

Edit; No place to tie it where I'm located.
 
Last edited:
I've propped a lot of planes and taught a lot of people to do it. I agree that chocks aren't the best solution, but sometimes they're the only solution. If I had an inexperienced person on the controls, I'd probably have chocks in place as well. I used the big rubber chocks for 18 wheelers when I didn't have a way to tie the tail or anyone to hold the brakes.

The video is a Cub and we all know that propping a Cub is almost like cheating! You can prop it from behind and reach the throttle if something goes wrong!
 
Shepherd said:
I was thinking about installing a parking brake, then realized I would never trust it. It would only have to slip once while I'm standing in front of it to spoil the rest of my (short) life.
Click to expand...
I've owned a couple of Cessna 140s and a Luscombe and none of them had working parking brakes. I was told by my old, wise instructor not to bother fixing it and to never use it even if it worked. He said you can take off with the parking brake on by mistake, but landing with one on will ruin your day.
 
Shepherd said:
Once the wheels were up against the chocks the chocks have to be pulled forward to release them. sigh...
Click to expand...

Once you're seated and ready to go, if the idling engine is pinching the chocks you can usually give it a brief shot of power to ride up against the triangular shape then pull them off as the plane backs off from that action.
 
dbahn said:
Once you're seated and ready to go, if the idling engine is pinching the chocks you can usually give it a brief shot of power to ride up against the triangular shape then pull them off as the plane backs off from that action.
Click to expand...


Worst case it would jump the chocks, also solving the problem, no?
 
Shepherd said:
Chocks are a necessity for me. No parking brake.
I made my own chocks by cutting a 4x4 diagonally. They work fine.
I tried the long rope, self removal thing. Didn't work. Once the wheels were up against the chocks the chocks have to be pulled forward to release them. sigh...
I was thinking about installing a parking brake, then realized I would never trust it. It would only have to slip once while I'm standing in front of it to spoil the rest of my (short) life.
Chocks it is.

Edit; No place to tie it where I'm located.
Click to expand...

You prop a Cub from the front? Having a right side door makes propping from behind so easy. One hand on the prop and one on the door post.
 
Shepherd said:
I tried the long rope, self removal thing. Didn't work. Once the wheels were up against the chocks the chocks have to be pulled forward to release them. sigh...
Click to expand...
It would seem to me (and bear in mind, I haven't DONE this) that attaching the rope on the far side might help. In other words -- each wheel gets a chock with the rope attached to the left side (outside), if you're pulling it in from the right side. That way it's going to try to pull the chock with a twisting movement. Just a thought. I've never hand propped, and only been around someone doing so once... it was a little Cassutt; two of us stood in front of the horizontal stab while he started it and got in. Reminded me of the days of flying R/C with Dad, the plane was just a bit larger.
 
Stewartb said:
You prop a Cub from the front? Having a right side door makes propping from behind so easy. One hand on the prop and one on the door post.
Click to expand...

I prop the Cub from behind.
You can't do that with the PA-17. Not enough room.
Prop from the front then run around the struts, landing gear ducking under the wing and around the door, which usually slams shut, to get to the throttle.
I also have the added task of removing the safety tape hanging from the aileron horns as I remove the chocks.
The safety tape is to prevent people from splitting their heads open when they duck under the wing.
Three people have been wounded, myself included on those little beauties, since I've owned the plane. I just bled copiously. The other two needed stitches.
Here is my process:
Roll it out facing down the alley. Insert chocks.
Back to cockpit.
Put the seat belt around stick and pull it tight for full up elevator.
Set altimeter. Make sure mags are off.
Back to prop.
Pull the engine through a few times.
Back to cockpit.
Prime. Make sure mags are off.
Back to prop.
Pull engine through a few times.
Back to cockpit.
Mags hot.
Back to prop.
Yank it to crank it. Usually it will start on the first prop. Except in winter. Expletives and bad words deleted, winter!
Back to the cockpit. Open door, which has conveniently slammed shut.
Fiddle with throttle until it runs smoothly and I can throttle back to idle.
Walk around back of plane to left side.
Remove left chock and safety tape.
Walk behind plane to cockpit. Stow chock and tape.
(Left side first. If the plane gets away for some reason it will turn right and hit my hanger door, not someone else's.)
Remove right chock and safety tape. Stow chock and tape. Secure cargo net.
Now, the most dangerous part of the process.
I have to back into the plane, butt walking backwards on the seat, getting my legs over the right hand stick without smacking into the throttle.
Then I have to get my left leg over the left hand stick without smacking the throttle.
I can finally get my feet on the brake pedals.
This is why there are no short flights in my plane (reference to How short is too short.) After all of this, I'm going flying, and I'm flying until the fuel is done.
I should make a video.
 
I made a light version of a glider/banner tow hook for my homebuilt Jodel. Released from the cockpit. A few short lengths of rope aboard, and I could usually find something to tie it to, leaving that bit of rope behind.

I also had some effective parking brakes. That engine started easily with the throttle at dead idle.

Chocks? As an inveterate inventor I would design a triangular chock that has hinges along all three edges, and another hinge in the center of one face. The rope would attach to a triggering mechanism that releases a lock holding that hinged face straight, allowing it to collapse inward so that the chock flattens out. Taxi over it and retrieve via the rope.
 
DaleB said:
It would seem to me (and bear in mind, I haven't DONE this) that attaching the rope on the far side might help. In other words -- each wheel gets a chock with the rope attached to the left side (outside), if you're pulling it in from the right side. That way it's going to try to pull the chock with a twisting movement. Just a thought. I've never hand propped, and only been around someone doing so once... it was a little Cassutt; two of us stood in front of the horizontal stab while he started it and got in. Reminded me of the days of flying R/C with Dad, the plane was just a bit larger.
Click to expand...

That's how the chocks in the original post work. The rope passes through the right side chock so when you pull it the left chock departs the left wheel first. If there's any doubt I give it a quick tug as the left chock approaches the right chock and it knocks it out from in front of the right wheel and then you just reel them both in from there. The right chock fits inside the left chock and the rope fits inside that chock, and they both can be stored under either front or rear seat.
 
I guess I could use my Jump Pack as a chock if it failed to start my plane. So far that hasn’t been a problem.
 
dbahn said:
That's how the chocks in the original post work. The rope passes through the right side chock so when you pull it the left chock departs the left wheel first. If there's any doubt I give it a quick tug as the left chock approaches the right chock and it knocks it out from in front of the right wheel and then you just reel them both in from there. The right chock fits inside the left chock and the rope fits inside that chock, and they both can be stored under either front or rear seat.
Click to expand...
Right, but the rope is pulling each chock pretty much straight out perpendicularly from in front of the wheel. What I'm talking about is placing the chock with the rope coming off the left side so that the chock gets pulled out with a clockwise rotating motion, as viewed from above. Again, just a thought.
 
DaleB said:
Right, but the rope is pulling each chock pretty much straight out perpendicularly from in front of the wheel. What I'm talking about is placing the chock with the rope coming off the left side so that the chock gets pulled out with a clockwise rotating motion, as viewed from above. Again, just a thought.
Click to expand...

Yes, that's easy to do. You can see how the rope placement is set on the outside of the triangle to help rotate it away from the tires.

Clipboard01.jpg
 
You must log in or register to reply here.
Back
Top