Winching

[bob888]

I recently installed a winch in my hangar to pull the plane up the hill and into the hangar (to save my back and my wallet). I have been connecting the winch cable to the tail tiedown ring but I notice that the ring is bending under the strain. This is the Van's forged ring that they sell on the web site. My question is whether this is a problem with the ring (soft material) or whether using this as a tow point is a bad idea and may overstress the attached structure. Anyone else have this issue?

[Gary7A]

I alleviated that problem by using a couple of these in series:

https://www.mcmaster.com/springs/spr...ion-springs-6/

Don't remember the size but can check the next time I'm in the hangar.


Gary Kohler
Ohio

[Kyle Boatright]

That structure is designed for *mostly* vertical loads. I would not pull it horizontally on a routine basis, especially pulling against the tie-down ring, which increases the bending moment.

If I was going to pull the airplane using the tail tie down hardpoint, I'd fabricate a piece of steel with a pair of holes in it. One the diameter of the tail tie-down and the other sized for whatever hook you're using to pull the airplane. I'd bolt the piece of steel to the airplane using the tie-down ring and attach the winch to the other hole. That will greatly reduce the bending moment on the assembly. The loads may still be too high for the underlying structure over the long term.

With a little ingenuity, you could probably attach a Y shaped harness to the main gear and pull it that way. No structural issues with that approach.

[Bill Boyd]

I believe others have made a Y-bridle to attach to the steps near the fuselage for a winch attachment point.

The winching I plan to do into the hangar at home will be on almost-level concrete so I hope the tail tie-down ring will take the load well enough, but if not the other ideas presented here should work.