53 Cowl doors

[GAHorn]

I”ve always been careful to restrain my Hartwell latches but (sigh) I discovered one of them had broken-out the edge of my door on a trip. I believe someone may have looked inside and didn’t know about this matter. (The only satisfaction is knowing they probably got “thumped” on their thumb!)

I once bought a dozen of the Hartwells online from a guy in Canada and he shipped them in a plain paper bag! The Post Office delivered the torn-open bag to me and offered me a claim-form for the “lost mail” office in Atlanta. Of course, the latches were never found and so I filed on the postal insurance.
Guess what...?? Postal insurance only covers the SENDER... so the $#%%@#$ guy who sold them to me got PAID TWICE.... and I never got anything at all!

Hartwells used to be $5-$15 but when Cessna began putting 20 of them on each Citation Jet the price went to Jet PRICES!

[daedaluscan]

Door number two!

2DB39DD6-79A5-43B2-9523-93E2B58FD640.jpeg

Nice job but I am curious why you want that door if that’s an O-360 under their?

I only have a left side door, and over the last 1000hrs it has fretted enough that it needs replacement. I am thinking of just patching it over. I’m installing an O-360 now and am planning to leave it until I get around to painting the cowling, and then removing it. I put a small oil door on RHS.

[DaveF]

Darn it, Charlie, *now* you ask me that! I guess I never thought about closing off the space because I like having the door for preflight inspections.

My mechanic was bugging me to improve the door design with Camlocs or Dzus instead of the Hartwell latches. Something like Ron mentioned a couple of pages back. I probably should have, because the "land" on the cowl is pretty eroded along the right side and there's not enough surface area. So I need to do something there anyway.

George, I was lucky that the latches on my existing doors were good enough for re-use. The pins were worn, so I replaced them with cotter pins. That was a good thing to do anyway during rebuild because it's a lot easier to rivet the latches in place if you disassemble them first. I clinched a few rivets on the first door before seeing that.

Also, a small cotter pin will prevent over-opening and breaking out the tab.

[DaveF]

I’d say better, nice work on the latch cut-outs.

Hours of fun with small files!

[daedaluscan]

I do see your point for pre-flight. I am going to leave it as it is and then decide down the road. Oil cooler hoses and the battery is there if I ever need to jump, so maybe I will keep it. I actually think I should have put another on the RHS. Its on the not essential list before I get back in the air.

[cessna170bdriver]

...Hartwells used to be $5-$15 but when Cessna began putting 20 of them on each Citation Jet the price went to Jet PRICES!

As I mentioned when this post started a couple of years ago, Del Lehmann at Mountain Airframe had acquired a lifetime supply of surplus Hartwell latches a couple of years before that. If I needed one now, he’d be the first person I’d call.

[DaveF]

The Hartwell H-5000 latch has a lot of variations for differing door skin thickness and bolt offset. Door thickness is the height of the trigger button, and the bolt offset is the thickness of the frame/land. Larger door thickness will make the button stand higher above the mounting surface to be flush with the outer skin surface. Larger bolt offset puts a larger joggle in the latch bolt. These thicknesses are stamped on the latch. If you buy surplus latches, check the values to make sure the latches will work for you. They're not critical and you can almost always make a different thickness/offset work.

I just posted a pdf of the spec in the Maintenance Library. It has pictures showing what I've attempted to describe above. I didn't see a spec already in the library. Sorry if there's already one that I missed.
viewtopic.php?f=26&t=15564