NO Wing inspection Holes

[6298]

The rear wing strut should have a large plate around it. That is where the cables and pulleys are. I looked at several metal wings I have removed over the years and they had some round inspection holes. I also found a metalized one that had no inspection holes except one just behind the front wing strut.

[6643]

The original wings had only the hole where the aft lift strut attaches and another for the connection to the pitot tube. When an issue with the drag and anti-drag wires was uncovered an AD was issued requiring the other holes. They have nothing to do with cables, pulleys or corrosion. The AD makes no exception for metalized wings, so, absent specific information from the STC itself, if you have the wires, you need the inspection holes.

As far as corrosion goes, back in the '40s the coverings only lasted about 5 years, so the wings got a very thorough inspection every 5 years or so.

If you don't have a 337 for the metalizing, and you don't have knowledge of what STC was used, you've got a bit of a problem. Somewhere, I have a list of just about every STC that's ever been issued for these planes. Problem is, a lot of them are not active. What I would try to do is identify an STC that your configuration appears to conform to and get an IA to inspect your wings and sign them off. Absent that you can try for a one time approval of the wings in their current state. First, I would make sure there's no mention of metalizing the wings, or replacing the wings with wings from another aircraft. If there is, maybe you can get the records for that plane.

I forget, but someone else can probably tell us if the wings carry a serial number anywhere; of course, with no inspection holes, you might not be able to see it...

[cweyant]

Thanks John. I'm getting nowhere. About to put the project for sale and return to experimentals.

[6643]

Did you order the FAA records? If you did, and there's no mention of metalizing the wings, have you worked with an IA to get a field approval? Or, strip the metal off and recover them...

[regular122]

Thanks John. I'm getting nowhere. About to put the project for sale and return to experimentals.

Here is a 337 from my Cessna 140 when serving as a Sinclair pipeline patrol plane. They metalized the wings in 1954 then reinstalled fabric wings a couple of years later. The 337 does speak to the location of inspection covers. Not sure if all were included. Maybe this helps. Steve

1954_Metalized_Wing_337a.png (466.19 KiB) Viewed 5158 times

1954_Metalized_Wing_337b.png (401.29 KiB) Viewed 5158 times

1954_Metalized_Wing_337c.png (428.8 KiB) Viewed 5158 times

[8170]

FYI I am still working on a kit for window latches. I have machined Aluminum set done and working on a 3D printed version that is strong enough. More to come..

[V529]

The original wings had only the hole where the aft lift strut attaches and another for the connection to the pitot tube. When an issue with the drag and anti-drag wires was uncovered an AD was issued requiring the other holes. They have nothing to do with cables, pulleys or corrosion. The AD makes no exception for metalized wings, so, absent specific information from the STC itself, if you have the wires, you need the inspection holes.

As far as corrosion goes, back in the '40s the coverings only lasted about 5 years, so the wings got a very thorough inspection every 5 years or so.

If you don't have a 337 for the metalizing, and you don't have knowledge of what STC was used, you've got a bit of a problem. Somewhere, I have a list of just about every STC that's ever been issued for these planes. Problem is, a lot of them are not active. What I would try to do is identify an STC that your configuration appears to conform to and get an IA to inspect your wings and sign them off. Absent that you can try for a one time approval of the wings in their current state. First, I would make sure there's no mention of metalizing the wings, or replacing the wings with wings from another aircraft. If there is, maybe you can get the records for that plane.

I forget, but someone else can probably tell us if the wings carry a serial number anywhere; of course, with no inspection holes, you might not be able to see it...

I've seen lots of wings off and never recall seeing a s/n anywhere. Modern aircraft have data tags on the various larger components, but I don't think Cessna started that until the 1970's and then only on the twins. (that I'm aware of) Most of the 1980's production had serialized data tags on even the ailerons and elevators. Our aircraft.......nah, probably not.

[6597]

I have found a number of sorts on my left strut, "L" for left presumably, "596" for where it the series it was built perhaps...nothing on wings I've seen. 596 doesn't match my serial number to the airframe or anything else I'm aware of...

[cweyant]

Thanks for the 337 copies Steve. That might be of some help. I appreciate the effort it took to copy and download that document.

John, do you think after drilling out all 5,000 rivets of the metalized wing to go back to fabric, that the wing structure might be compromised some how? I've got two fellow pilots trying to get me to either purchase new/old rag wings or remove the sheet aluminum and reinstall fabric.

[cweyant]

Received the FAA CD. No STC for metalizing the wing!