The Cessna 120-140 Association Forum

Hello all,

I am just about finished prepping my 46 C-140 wings for covering and have a question regarding the saw tooth tabs in the aileron bay. It is my understanding that these were used with the original (cotton ?) fabric and dope . I am re- covering with Stitts poly fiber and am wondering if I should set the tabs flush thereby allowing the fabric to lay down tighter in the curve. Were these tabs only necessary when dope was used to shrink the fabric instead of heat ? Is it considered an alteration to do this or a bad idea ? Are they not needed with the modern fabrics ? I’m curious as to what some of you may have done on your re-covers and would appreciate any input and information . Thanks,
Mike

I'm surprised none of the gurus haven't responded, so I'll take a few minutes. Since I go way, way back to the Grade A days etc - all of your assumptions are correct - just flatten them out and follow the Polyfiber manual with the appropriate overlap with the dope - Ray Stits (Polyfiber developer) did extensive testing to get his process approved by FAA. Just be very cautious in the sanding phase when going over any "bumps", one can go thru the dope into the fabric. No it is not considered an alteration per se to flatten the " tabs" but of course your recover is an alteration under the STC.

Big Edd

I will be putting new fabric on my 140 starting this morning using the Stewart system.
I flattened the tabs out.
It will be much neater and cleaner.
Plus it gives more clearance for the control surfaces.
Watching the Stewart systems video, the Piper that they were doing it had no tabs to deal with and there was no question of the strength of the glue joints.
I know that the Piper never had the tabs to begin with, but to me it shows that they are not needed.
Another gentleman on the field that I talked to last summer flattened them on his 140 and it worked fine.

Good luck.

Rick

Thanks Big Edd and Rick ,
It seemed like the way to go . I couldn’t find any reference to it in the Stitts manual other than mention regarding the overlap in the aileron bay. I’ve seen the Stewart Systems videos as well and it looks great. I don’t personally know anyone who has used it while I have a few friends who used the Stitts so I went with that. I don’t think you can go wrong either way. Thanks again for the responses!

Mike