Oil door in cowl bowing in flight

[JackinMichigan]

The access door on top of the cowl has a significant bow to it while in flight. I've made the habit of taping it down with military grade duct tape, but that won't be an option once I get it painted. I feel as though I need to stiffen this door somehow. It's contoured to the cowl, so a simple fat bar stiffener won't work here. Anybody got any ideas?

[Zuldarin]

I epoxied two plies of carbon fiber to the under side of my oil door and that seemed to work for me.

[rocketman1988]

I used Soric fabric. Interesting stuff, goes on like fiberglass cloth but doesn?t absorb the epoxy except in the hexagon cells. Makes the fiberglass sheet 8 times more rigid, according to the literature...

[N941WR]

Jack,

Get some aquarium tubing from your local pet or hardware store. It doesn't have to be very large diameter.

Fiberglass it under your filler door. Three layers of the BID most of use should work. Your call if it you want to make it an X, a box, or both. Leave the tube long enough you can just pull it out, after the fiberglass hardens. Tape your door shut with the tape to it holds the correct position.

Be CAREFUL not to fiberglass your filler door shut. You can always remove your top cowling while you do this.

That will stiffen the door significantly and keep it from flexing in flight.

BTW, are you flying out of 1D2? I learned to fly there many years ago! Say "Hi" to Doug S., when you see him next. We were roommates at Western.

[Scott Hersha]

Mine bowed also. I installed two ribs - fluted to make the curve - on my first RV8 with the fiberglass door. On my current RV8, I made the door out of .063 aluminum and it doesn?t bow at all, and lays down nice and flat.

[dtw_rv6]

Mine started popping open in flight, so I had a buddy lay up a carbon fiber rib on the back of mine about 1/2" wide running from top to bottom. We preloaded the door slightly flatter than perfect fit, and everything looks great after the last two hundred hours. Carbon fiber is really stiff, and I think that it is generally easier to work into organic shapes than fiberglass.

I don't have any photos handy... sorry.

[JackinMichigan]

Originally Posted by N941WR

BTW, are you flying out of 1D2? I learned to fly there many years ago! Say "Hi" to Doug S., when you see him next. We were roommates at Western.

I got my license at Kitze Aviation out of 1D2 and I live maybe 1-1/2 miles from that airport. Unfortunately there's a multi-year waiting list for a hangar out there, so currently I'm at Willow Run (KYIP).

[N941WR]

Originally Posted by JackinMichigan

I got my license at Kite Aviation out of 1D2 and I live maybe 1-1/2 miles from that airport. Unfortunately there's a multi-year waiting list for a hangar out there, so currently I'm at Willow Run (KYIP).

Small world. Back when I got my license there, it was a Cessna Flight school, we flew brand-new 152's and I lived in the apartments off the north end of the runway.

Talk to Doug, the other day he mentioned he was thinking of selling the 120. That will free up a hangar but I'm not sure if your -10 will fit in it or not.

[BillL]

Originally Posted by rocketman1988

I used Soric fabric. Interesting stuff, goes on like fiberglass cloth but doesn?t absorb the epoxy except in the hexagon cells. Makes the fiberglass sheet 8 times more rigid, according to the literature...

It needs a layer of glass over it. I tested the stiffness, and it was more than 8 times stiffer for a 2-core-2 vs 4 layer. 3mm Soric

[wjb]

No flight test yet, but I'm following the recommendation from elsewhere on the site to save the cut out piece of the cowling and bond it to the bottom of the oil door. This extra piece of glass should significantly stiffen the structure (stiffness goes up with the cube of the thickness; should be at least 8 times stiffer!)