Brodhead Pietenpol Association

Hi folks,

So, I have this nice 6’ length of ms2001 aluminum aileron hinge about to get attached to my ailerons. The pin is the exact length of the hinge. I’ll need some extra length of the pin to bend and secure to the structure once the hinge is attached. Did you trim the length of your hinges to get the extra pin length (how much “extra pin length, 3”?) or did you buy 6 1/2’ of pin dowel, pull out the shorter length and replace with the longer one?

Thanks!

Boy, now you've got me wondering how my aileron hinges are set up. I've got piano hinges all right, but my assumption is that there is only one way in or out for the hinge pin... from the wingtip end. I'll have to look to see how mine are done.

Oscar Zuniga
Medford, OR
Air Camper NX41CC, A75 power

Thanks, Oscar. I ask because I’m finding it difficult to find a hinge pin longer than 6’, which leads me to think that there are actually two hinge pins per piano hinge, one secured from one side and another (3’+) coming in from the other? It would seem that a builder would use a pin longer than 6’ and secure it to the structure, but I don’t know where to find a hinge pin longer than 6’.

On Cessna's the pins are slightly short and small cotter pins are installed, one each end through the hinge, to retain the pin.

Bobbyt;

I ran out to the hangar to look at the aileron hinges on my plane. Let's see how I can put this. There used to be a TV commercial for women's brassieres, the main feature of which was "there's no visible means of support". Such is the case with my full-span aileron hinges

The inboard ends of the pins are captured, of course, by the aileron cutouts, which prevent the hinge pins from sliding very far inboard if there was a force acting on them to want them to do that. The outboard ends, however, are not bent, pinned, or fastened in any way. I suppose if a pin wanted to walk its way out the tip end of the wing, I would spot it before a couple of feet of it were hanging out in the breeze, but in theory even releasing the hinge part-way could put it in a bind or subject it to flutter. So far, nobody has said anything about the pins and they've been inspected on many occasions by many A&Ps and of course the two original builders of the plane and myself, on many, many occasions.

-Oscar

PS, I think when my plane is sitting idle in the dead of winter this winter, I'll get a drill block, pull off the ailerons to get to that half of the hinge, and go look at how Cessnas are drilled and drill mine for small cotter pins or safety wire.

-Oscar

Thank you.

Wow, okay. I think I would want some way of knowing it was secured, though. I really appreciate the input.

Richard Roller wrote: ↑Wed Nov 08, 2023 2:16 pm On Cessna's the pins are slightly short and small cotter pins are installed, one each end through the hinge, to retain the pin.

This is a great solution… Thanks!

I have also seen hinges (on a/c with short hinge sections, 6"or so) where the hinges were crimped on the ends to retain the hinge pins. That works fine in applications where the hinge attach hardware is easily removed. I would think that would be awkward with a 6 foot hinge section.

Chuck; thanks for the photo of the cottered hinge pin. Yeah, that's gotta be a 1/16" hole and those usually cost me a few drill bits when I make the attempt to drill them, especially if I can't use the drill press. Wrong feed and/or wrong speed, and -snap!- bye bye drill bit. Also, those hinge pins are made of material that's harder than the bars on the gates of Hell, and that makes it even more "fun" to drill those small holes. But I'm going to try it.

-Oscar

RPM is your friend.