Be careful in rigging your flaps!

[Randy]

I was in the cockpit ready to start the engine. I flipped the switch to raise the flaps and looked over to verify they were moving. To my horror the left flap was jammed against the outboard top skin and was bending it into an horrible looking mess.

Now, part of my paint prep will be replacing the left outboard top wing skin.

This is apparently not all that rare of an occurance as Van's tech. told me they routinely raise the flaps up from full down position a few degrees before letting people get in.

There needs to be enough overlap distance of the flap up under the skins so that leaning into the flap with your leg when they are fully down, doesn't let the flap skin jam against the top skin. I had to rework the bottom inboard part of my flaps a bit to allow them to be rigged a little higher, with a little more overlap to prevent this from happening again.

I originally rigged them per everything I could read about the subject. I used the tooling holes in the ends of the wing and temporarily mounted the flaps and airlerons when drilling the rear spar holes so that everything would be nicely lined up, and everything did line up very well and my wing incidence is dead on, the airplane flies straight and true.

The bottom line is that a priority needs to be placed on that skin overlap so the flaps cannot jam and cause this kind of damage.

This is not a danger in flight as air loads will keep the flaps flexed toward up position. Only a problem when raising them on the ground. Manual flaps would also have prevented this from happening. That flap motor is strong.

Randy C
RV7A

[grimr2]

I guess the positive is that you caught it the first time.

Do you have any pics to show the damage? And, does the flap motor have a limit switch?

Just wondering....

[Jerry Cochran]

Originally Posted by Randy

I was in the cockpit ready to start the engine. I flipped the switch to raise the flaps and looked over to verify they were moving. To my horror the left flap was jammed against the outboard top skin and was bending it into an horrible looking mess.

Now, part of my paint prep will be replacing the left outboard top wing skin.

Randy C
RV7A

Randy,

You mean you have to replace the entire skin for this? Isn't there a way to just repair the bent part? Got any pix?

Jerry

[94kb]

I had a similar thing happen to my RV-6A last year while leaving Oshkosh. I had my flaps down during the show. Either my passenger or someone looking into the plane leaned on the flap causing it to bind with the inboard leading edge. While retracting the flaps, I noticed they stopped before being fully retracted. When looking at the passenger side it was easy to see the problem. I put them back down and the pushed the leading edge down. I thought everything was ok, but a couple of days after returning I noticed a ripple in the inboard trailing edge -- bummer.

I tried to fix the damage by bending it back in place but it had stretched the skin. I had to use my shrinker which caused some marks in the skin requiring sanding and repainting. I didn't replace the top skin and is only slightly noticeable because the basecoat/clearcoat is hard to match. I think if you haven't painted yet, you may be ok.

Good luck,

Ken

[Hum]

I've had this happen also..ugly :-( I no longer leave my flaps fully down on the ground!!

[Mel]

I have my flaps set up for a maximum of 38?. This leaves sufficient overlap so that this doesn't happen. Been flying N168TX for 21 years without a problem.

[Bavafa]

Originally Posted by Jerry Cochran

Randy,

You mean you have to replace the entire skin for this? Isn't there a way to just repair the bent part? Got any pix?

Jerry

This happened to a good friend of mine and it looked ugly. It was fixed successfully without removing the top skin as that is a painful process. Feel free to drop me a note as how it was fixed and I will be happy to go over that.

[airguy]

Originally Posted by Mel

I have my flaps set up for a maximum of 38?. This leaves sufficient overlap so that this doesn't happen. Been flying N168TX for 21 years without a problem.

I like that idea, I think I might adjust mine up a bit, they are currently set at the plans-standard max travel. It would be a rare landing indeed where those last few degrees of flap travel would be critical.