URGENT COWL DOOR INSPECTION NOTICE

[DaveF]

MIT, Great idea on posting pictures of the various modifications to the cowl door. Hopefully folks with the 170 and 170A planes will also post pictures.

Sadly, I don't have any pictures of mods or fixes. All I have are pictures of doors in need of repair. It's a '54 with one door on each side of the cowl.

overlap is fretted away

missing metal

When you guys rebuild your doors, do you spot weld the doubler?

spot weld

[GAHorn]

I consider the missing-metal as merely cosmetic. This is usually caused by repeatedly allowing the Hartwell latch "tongue" to "snap" open unrestrained when opening the latch. The tongue over-travels and first bends, then works the missing-area until it departs.

One should always use a finger to retard-and-contol the tongue when releasing the latch.

Another tip: RE-close the Hartwell latch before allowing the door to swing open and ride/rest against the lower cowl. An open tongue on the latch will scratch your lower cowl permanently.

To prevent "smoking" and thinning of the metal door where the door slips beneath the upper cowl.... install teflon tape on the door edging.

[170C]

George, I have put Teflon tape on my oil door, but where the back engine baffel needs the tape, I am having a problem (also on the top of the door) keeping the tape stuck to the metal. I have cleaned it with 100LL, acetone, mek, etc. and it still doesn't want to stay attached more than a few weeks. What are your suggestions for cleaning the vrs areas and attaching the tape?

Could just be that the GREEN airplane is so fast it pulls the tape off, but then again maybe not

[GAHorn]

I"ve not had any problem with the tape sticking after cleaning with acetone, but you might have old tape? You might want to try contact cement like 3M 1300L Let it dry ...THEN apply the tape.

[MoonlightVFR]

I viewed a video of a 1953 C170 , Year 1953 with extensive mods. Video was about a RadioControl electric tailwheel tug.

After the owner showed the 180 hp eng mod. I noted that he had Four ( 4). Hart well style latches on the left cowl door.

I was quite surprised. FOUR. latches instead of two.


Regards

[Bruce Fenstermacher]

I viewed a video of a 1953 C170 , Year 1953 with extensive mods. Video was about a RadioControl electric tailwheel tug.
After the owner showed the 180 hp eng mod. I noted that he had Four ( 4). Hart well style latches on the left cowl door.
I was quite surprised. FOUR. latches instead of two.
Regards

Does the plane in the picture that johneeb posted on page two of this thread look familiar? It is the same one being dragged around by that R/C tug.

[dbarron]

So is anyone making new doors??

[GAHorn]

I once inquired of a professional metal shop owner what it might cost to fabricate/install a new door and the price was astonishingly high. I'm certain Cessna could also astonish.

[4517C]

I have modified both my cowling doors with a backup safety system and the doors do not move in flight. This is after experiencing a door springing open at cruise. At the top of each door, at the midpoint of the overlap and in the center of the door, I installed a 3/16 rivnut. I then drilled a mating hole through the stationary cowling. I use a 7/8" diameter black knob with 3/16 10-32 stud to securely fasten the door to the cowling as a backup for the two main latches. Before the modification, both doors would bulge outward 1/2" to 3/4" in flight. You can imagine the loss of positive pressure in the upper part of the baffling, thereby reducing cooling. Now, you cannot see either door move. Jake

[Dennis]

I'm not sure what all the fuss is about. One of the first repairs I took on after purchasing 9er1Charlie was cowling doors. I purchased 4 new latches from Cessna and new hinge stock from Spruce and WALA problem solved. So if your replacing latches take a good look at the hinges, they will be worn out as well. Just like the previous pictures. Regards, Dennis

[edbooth]

My thinking on the mostly left door failure is that this is the one that is opened most frequently and the latches get the most wear. I have a "53" and have had to replace the door and latches on the left side. Right side is still very secure and tight. I built a new door using the old one as a pattern. I chiseled off the spot welded doubler cut out a new one and flush rivited it on the new door instead of spot welding. Installed new hartwell latches and it has worked good for the last 27 years. Its as easy build.


Ed Booth, Trenton, SC

[cessna170bdriver]

My '55 model came to me in 1982 with four latches on each cowl door. It was a while before I knew they all didn't come that way. A couple of them had broken springs, and just before I had the airplane painted in 1984 I ran across a good deal on Hartwell latches at Sun-N-Fun ($2.50 ea. IIRC) so I replaced all 8 of them. The only problem I've ever had with them in the ensuing 1800 hrs was poor preflight... twice in almost 30 years.

[dbarron]

I just rebuilt brand news doors for mine.. They turned out perfect. Since I am all tooled up for making these, I am ready to make up/rebuild any more if there is enough interest in them. I can send a picture of how mine turned out if requested. These are the best fit I have ever seen and they are rock solid. I cant take on any more work until I get my project finished this summer, but after then I could.
We have a top notch metal shop with top quality standards.

Dillon

[marathonrunner]

When I was rebuilding my 55 I had very worn doors. I made new ones and instead of spot welding, used flush rivets. Looks very original. In addition I used some Akzo paint for the doors where they rub and also where the baffle seal contacts the cowling. It is the paint they use for high abrasive areas on jet blast areas. It has held up well for around 1100 hours now.

[4517C]

When I looked at this photo the other day I realized it clearly showed my cowl door backup latch. The 10-32 knob threads into a rivnut. Jake