Flap Attachment Woes

[SteveHRV7]

I was installing the flaps tonight on my QB 7a wings when I made my first big mistake ? I installed the piano hinge for the flaps in between the skin and the flap bracket. No problem ? I drilled out the rivets and reinstalled it in its proper place on the outside of the bracket. Only problem was that in drilling and tapping out the rivets I inadvertently caused the piano hinge ?loops? on the wing side to get out of alignment with the matching ?loops? on the piano hinge on the flap. Net result is that the pin would not go through. Any suggestions on how to realign a piano hinge?

Also ? I see that this pin extends through a hole that needs to be drilled in the aileron bracket. How do you secure the pin so it won?t move and interfere with the aileron?
Thanks double!

 

[jsharkey]

One way to secure the pin is to drill the hole in the aileron bracket slightly off center of the piano hinge line. This way you can flex the the pin all the way through the hole and it will "spring" past the bracket and remain trapped. Removal will require some dexterity - and long nosed pliers.

I made the pin longer than necessary and bent the end over so that it lies flush with the outboard end of the aileron bracket. I then safety wired the bent end to the bracket. You need to be sure that it is well clear of the aileron as things get tight there. It's also a Must Check item on my pre-flight.

There are other methods out there including removing a couple of center loops on the hinge and installing two shorter pins from the center - a bit like the seat backs.

Jim Sharkey
Rv6 - Phase 1

 

[Ironflight]

Hi Steve,

Oh heck, those aren't big mistakes! Many folks re-do their flap hinges at least once....

Hinge material is CHEAP - if you've bent the things out of alignment, just buy a six foot length, split it, and use half for each wing. If this is the most expensive replacement part you get, it will be unusual. Think about putting the hinge pin in while you rivet - it stiffens up the somewhat flimsy piano hinge, and might keep the loops aligned.

On the flap installation, Van's gives you two methods - the single long pin with the hole in the aileron bracket, or the split pin - cut the pin in half, and remove a couple of hinge loops from the middle of the flap and wing. Insert the hings from the middle, with a little "L" shaped bit you safety wire to the flap brace. Lots of folks do it this way - I personally find it much easier.

Paul

 

[SteveHRV7]

Fixed it with a combination of the suggestion to split the flap pin and an hour or two of tweaking the loops on the hinge. The shorter pin minimized the slight imperfections in hinge alignment. Thanks!
Steve