cowling attachment hardware

K

kayakalex

New member
What hardware holds your cowlings on? The hardware on my '74 7ECA doesn't match the parts manual. I looked at several Citabrias at the NW EAA fest this summer and talked to some owners. No two set-ups were the same.

The Bellanca parts manual (1979 rev) calls out AN-526-1032-8 + AN960-10L for the lower cowling. That's a truss-head non-structural machine screw, 10-32 x 5/8" with a washer barely larger than the head of the screw. The top cowling is supposedly fastened with 85-11-240-16 studs, 85-34-101-17 retainers and 85-47-101-15 receptacles. Aircraft Spruce deciphers these as Southco 1/4-turn fasteners.

The holes in my cowlings look like they've opened up a bit over the years. The lower cowling uses flat head screws and countersunk washers. They look ok and work fine. An AN960 washer would probably just fall thru the holes.

The upper cowling uses 1/4-20 pan head machine screws and U-type speed nuts. Whoever made this change should have amended the W/B sheet :)

I'm just curious what other owners have done to compensate for the middle age spread of holes in fiberglass parts.

Thanks!
Alex
 
A few years ago the cowl on my 8KCAB was refurbished. There wasn't a problem with the AN 526 screws but all of the holes for the Southco fasteners had been elongated - so holes filled in and new ones drilled. From memory we had a Service Letter to reference.
It now has all standard fasteners except that the Southco studs are different lengths to cater for the extra thickness. It had been through this before so three or four different stud lengths used. Three hundred hours later I find that one or two holes should again be fixed up.
http://www.southco.com/product/partlist.aspx?cid=7438
 
Thanks, Dave. You answered the question I didn't know to ask: How to make the 1/4-turn studs engage at the correct depth. It sounds like quite a little project. I think for now I will just embrace the industrial look of my 1/4-20 pan head screws.

Alex
 
My 73 GCBC has 1/4 turn Camloc's on the top and Pan Head screws on the bottom. The top was a real bear to get off with the studs sticking through the cowling they hung up on the recepticals. You almost needed two people to pull both sides free to get it off. I removed the retainers from the studs across the back, now when I unlatch them I pull them out. The top is now very easy to remove, much easier than screws.
Regards
Morris
 
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