Hello to all of you!

My first post here, what a good web site!


Can someone guide me to obtain the factory recommended inspections applicable for smal skin cracks on the upper side of the wings and just outbord of the strut attaching area?
It is an old C-180 with low hrs on it. Must have been overstressed somehow. No wrinkles or bends, maybe 4 cracks each wing around 1/4 to 1/2 inches or less in lenght aligned over the main spar.

Has any of you gone through something like this to check for integrity/airworthiness?
Any experience you can share? We will start with a borescope I guess.
Plane has been flying like this for the past 1000 hrs I was told. Nothing in the logs.

Thanks.

Not sure about right on the spar area but I've seen some float planes they riveted a diamond shape doubler over the crack. I think they were about 2 inches in size.

Unless you can see what caused these cracks I would take a serious look. I don't know for sure if the wings are a structure that depends on the integrity of the skin like the fuselage is or not but if it is those cracks may be trouble, if not in an area that is structural then simply stop drilling may be OK. At any rate, you are on the right track to take a borescope and take a good look at the spars and mounting points.

Are the cracks at the rivets right along the ribs? If so, this is a common place where cracks can develop, especially right around Sta. 100. I have found a couple like this when doing Sportsman installs. It's now part of my inspection routine. Typically its just the top skin layer that cracks with no spar involvement. Can you post some pics here or eMail them to me? Hard to really say w/out seeing.

If its as described, drill out the offending rivets and install a diamond patch adding additional rivets. Pain in the but, but not really a huge scare.

Pretty common in single and twin comanches at ~4,000 TT; numerous owner’s have flown many hours with the cracks stop-drilled. Not very tidy looking, and I could never find any official guidance authorizing that repair, so we replaced the offending panels and placed more/bigger gussets. ‘Course that was 20 yrs ago when the shop rate was prob 1/3 of what it is now, and the FAA was knowledgable and relatively cooperative about signing off major repairs. It’s also easier to jig the wing in place with a low wing; we just epoxied cut to fit padded 6x6’s vertically on the concrete floor, then jacked up the A/C and knocked them over by hammer when we were done.

Download the maintenance manual from the 180 club website and look at the last chapter that covers repairs. The examples of damage and repairs are in there and will most likely cover your issue and help with you designing the correct repair. Should be simple as noted above.

Those are standard cracks. no big deal.
A diamond patch works well

Many thanks for the valuable comments!

I will post some pics around Jan 2.


Can the maintenance manual be downloaded without being a member of the 180 club? I´m no longer there.

Ditto what Tango Fox said. We see them all the time. Typically on the four rib locations between strut and tip. Will even be on lowtime pavement aircraft. Like has been said,, diamond patch and move on. Don't lose any sleep.

[email protected] wrote:Can the maintenance manual be downloaded without being a member of the 180 club? I´m no longer there.

This is all we have for docs:

https://backcountrypilot.org/knowledge- ... umentation

If anyone wants to donate more 180/185 documentation or manuals, it's welcome.

Good to know those cracks can be common.

Tks for the link.

Found this link for the C-100 series service manual, incuded the 180.

http://www.mennen.org/airplanes/Logs46Q/C185service.pdf

Zzz wrote:

[email protected] wrote:Can the maintenance manual be downloaded without being a member of the 180 club? I´m no longer there.

This is all we have for docs:

https://backcountrypilot.org/knowledge- ... umentation

If anyone wants to donate more 180/185 documentation or manuals, it's welcome.

Here’s a few of them

100 series service manual 1962 and prior http://rob.com/matt/manuals/150-185_sm_pre63.pdf

100 series service manual 1963-1968 https://www.redskyventures.org/doc/cessna-maintenance-manuals/Cessna_100_Series_1962-1968_MM_D637-1-13.pdf

180-185 service manual 1969-1976 http://www.mennen.org/airplanes/Logs46Q/C185service.pdf