The Cessna 120-140 Association Forum

Hello all,

Looking at a pre-buy for a local airplane, and this dent is 31 inches long, and run through two belly skins. Since the 140 has a monocoque construction, this makes me nervous.. it looks like its been there for a few years, and it is oil-canning. Now having al lot of experience with SEMI monocoque structures, I would say that is bad but not grounding. Does anyone have the excerpt for the Service manual on the 120/140? Im curious as a cat right now, and this one bothers me. Please advise if you have access to the data.
I am going to consult my AC 43-13 1B.
Thanks all,

Les

Another view of the belly skin......

last one, for some reason, only one was allowed, even though these three were uploaded successfully.

Buy it and fix it! It would be interesting to know the back story. It looks like it rolled over something..

Those skins are not that hard to make and replace. I agree with Randy, just fix it.

I would fix it eventually, but I’m rather concerned with it now. Have any if you seen dents like this in a 140 flying around? I would imagine it would weaken the structure significantly.
In order to replace I would have to jig the airframe and lots of accessing. I can do it, but I’m not certain of the MH I have to put in. I have three young kids after all. What do y’all think?

Randy brings up a very good point. You need to know what action cause the deformation specifically - lacking good /accurate info - one may be concerned about up front, engine and prop - any changes noted? To be ultra conservative, if flanged engine, prop hub flange runout may be prudent!

Discreetly, check to see if SWA has a DER on staff, if so, show him photo for an off-the-record opinion.

Without any tearing of the skin, only denting , with no warpage in adjacent areas, and it doesn't appear that the one former was not dented, I doubt is the structural strength was significantlly reduced.


On the lighter side, hello Bondo or J B Weld! 2c


PS If it's a problem checking for SWA/DER/DAR, I have local airport SWA retiree friend with 20K hours who was with SWA when they only had 6 planes and he surely knows.

That was my thought as well. The engine was replaced in 2015, but the paint is much older, so it doesn’t appear related but who knows! Gear area wasn’t cracked. Missing 40 years of airframe logs, and engine was last field overhauled in 1963. I was mostly concerned with the bottom end. The skin wasn’t the deal breaker, it was the asking price. I do have a DER at SWA though. Thanks for the advice! Continuing on my search!

Several things come to mind.

1. whatever they are asking, you can probably do better.
2. many of these aircraft have damage. Mine was destroyed in a windstorm. Anything is re-buildable.
3. A good friend of mine used to own a 120 over in Saginaw Michigan. The first log book entry.............."replaced both wings".
4. I've seen dents like that before, he probably taxied over a taxi light. Not tremendously serious and easily fixed, either by replacing skins or adding doublers.
5. Missing logs will hurt re-sale when you sell. And this will only continue.

Agree with your statement wholeheartedly. Rebuildable, most definitely, but when i assess anything now, I add in the cost of everything, i.e. corrosion, dents, cracks, engine overhaul, etc.. because im the one that has to work on it and fix it- most of us have been in that situation before! Emotion has to be taken out of the equation for buyer AND for the seller.
Some sellers think a 55 year old engine that was field overhauled, and lipsticked by putting on a top end, but it is a dangerous proposition. I dont think i cannot convince otherwise, especially if they paid too much for it. Now i remember how fun it was looking for an airplane...
Regards,
Les