Good Day All,

So I have a case of worn cowl flap hinges on a 73 Cessna 182P. They are worn and need work.

It has been mentined that there is a fixed cowl flap kit that can be used as well.

Anyone have any comments to make about changing to a fixed set? Good? Bad? Cost benefit?

The aircraft will be operated in Praire Country...so hot summers and cold winters!!

Thanks

Macdon221

The hinges are really not that bad to fix, and then they are even easier to slightly modify so it won't happen again.

There are two paths:

1) Drill out rivets of hinges, replace hinges with some new stainless ones (steel ones are actually better in this area, but I could only find stainless steel units). You can cut the hinges with a dremel tool, band saw, etc., very easily, and put them back to back to match up the old drill holes with the new hinges. Replace the hinges, then use annealed drill rod of the right diameter. Drill rod is easy to find in exactly the right size you need at a good hardware store, and annealing it will make it soft so it will wear before the harder-to-replace ss hinges will. Just use a plumbing torch to get it cherry red, then let the flame slowly work its way down the rod to let the receding material cool slowly. Takes about 10 minutes for each hinge wire to anneal, bend into the original hairpin shape of the old hinge wire with a pair of needle nose pliers, and anneal again.

I didn't have the right rivets, So I asked my mechanic to rivet on the hinges on the right cowl flap.

But for the left side,

2) I got a 2" metal hole saw, cut two holes on the deep formed inside area of the cowl flap near the hinge to create two access holes into the cavity you can use to put nylock nuts into. Then just make new hinges, and hinge wires, and screw the hinges on with AN button head phillips sheetmetal screws, and secure with the nylocks.

I think version (2) works the best. Easy to check/fix in the future if they loosen again; sometimes the rivet hole diameters are too wide when the rivets work loose.

But that's only 2/3 of the fix.

The hinges wear out on the right side from exhaust vibration of course, and less so for the left side. There is a little play even with new stock hinge wires. After your hinges are snug with the right size drill rod instead of the stock hinge wire to make them snug (not tight), you can clean the inside hinge area with whatever thoroughly, buy some ultra high temp black RTV, and lay a thick layer all along each hinge to completely cover the hinge from edge to edge. Place the cowl flaps in the closed position, and let it cure overnight. The RTV will completely eliminate excessive play in the hinges. This works just as well for older hinges that already have a lot of play- it magically goes away without excessive binding of the wire.

On mine, I saturated some dacron tape (sail scrim) with rtv using a squeegee, placed it along the hinge over the thick layer of wet RTV I had put there, and goobered on more on top of the tape. I did it because I thought it might help make it even stronger.

I got most of this advice from the CPA website, and believe me- it works. It saved me a lot of money ($~1k for a right cowl flap these days- the one that usually falls off). Ironically, I ran into someone who had just lost theirs this summer...and I thought it would be a good idea if every 182 owner just did this since all it really takes is a $4 tube of RTV, some cleaner, an index finger, a rag, and about 1/2 hour to do.

As an aside, I see *very* little difference in CHT flying high around home with the cowl flaps open or closed...about 25 degrees, and about 4-5 mph difference. I did notice about 50 degrees of difference at low altitudes (2-3k'). So the permanently open cowl flaps might be just fine if that is any indication.

First, though, I would try the above. At least the RTV thing. But I think I had an hour into cowl and flap removal, a couple hours running around finding drill rod and tools, 2 hours from start to finish on the left cowl flap, and 1/2 hour on the right side before I gave it to the mechanic to rivet the new hinges, another hour to install both cowl flaps and the lower cowl, 15 minutes to do the RTV thing, and quite a while to get the RTV off my hands.

Give it a whirl.