RV-7 Flap / Wing skin interference and fix

[drainge]

Hi all,

A few days ago, I retracted the flaps (on the ground) and noticed that the motion stopped prematurely. What had happened is that a portion of the curved leading edge of the flap had gotten caught under the wing's trailing edge skin -- when the flap was retracted, the material bent about the aft-most rivet line.

This likely happened because someone leaned against the flap while applying new wing walks and because I missed it in the preflight.

I dropped the flap by disconnecting the flap extension push rod. In that position, I was able to reform the leading edge of the flap, and to remove most of the deformation from the trailing edge of the wing. There still is a slight bend (and bubble) in the skin that is difficult to remove, I think because it is backed by the aft spar.

Any advice on remedying this situation without removing the wing skin? Any advice on ensuring it doesn't happen again in the future?

Thanks,
Dan

 

[sjhurlbut]

flaps

A common thing to make sure doesn't happen.

Not much you can do about it now - bend skin back as best you can.

Ensure at full flap retraction it doesn't go too far. Shorten flap push rod as required and tighten bend radius of flap leading edge.

 

[skypilot737]

Flap extension

Sorry for the bend. I think it happened because the flaps extend too far. You need to make sure the curved portion of the flaps have no chance of getting out from under the wing skin. If you shorten the extension of the flaps ( 44 degrees instead of 46 degrees) the curved portion will not get on top of the wing skin and you won't bend the wing skin.

 

[BruceW]

I have feared this happening on my -7 since at full extension, the rolled flap skin is close to catch on the back wing skin.

To hope avoid this, my taxi after landing procedure is to raise the flaps just a bit. Seems to have worked so far.