Rear strut condition

[johne]

Hi all
Had a A.I. conduct a buyer inspection on a 1946 C120 with 8,500 hrs TT on the airframe. I do have the STC letter for the metal wings (no diagram) and he was concerned about two items. First, there are no inspection holes (already read and liked previous posts about this topic) to do a proper Annual inspection. Second is he didn’t like that the feel of the rear strut on the right wing. He said it didn’t have the same tension as the rear left wing strut. He said it felt loose though there is no slop or rattle when he would apply force while grasping with his hand.
I’m told the rear struts washes the wing in or out and is not structural as the forward struts are. Any comments about this?
Also if I may add another critique he had. The right horizontal stabilizer when flexed from the end produced a oil can or canting noise and feel to it. There is no visible rippling to the sheet metal just the canting description. The left stabilizer does not do this.
Thx for reading
Johne

[rfrederick]

Johne,
I am not an A&P and I only have about 3 months with my 140.
But here is what I have to share:
The inspection holes were important to my IA during the prebuy. I don't know if there is some way for an IA to scope the wing without them.
I don't recall any noticeable slop my rear wing struts.
Definitely no canning noise on my stabilizer, I would have known as I spend some time on them trying to polish the tarnished aluminum.

There are smarter folks (than I) on this group who will give you better content

Hope all goes well with your acquisition.

[6597]

Regarding the oilcanning on the stabilizer, some do and some don't. I installed the 0432160 reinforcements on my stabilizer, I think some of the early ones did not have this.

channel and leading edge.jpeg (98.23 KiB) Viewed 4316 times

As far as the right strut not 'feeling' right, make sure it's a right strut and not a left one on the right side, see previous posts viewtopic.php?f=7&t=1110

I actually had a hangar neighbor with 2 left struts, couldn't seem to convince him of the error.

[johne]

Went back to take another look at the stabilizer canting problem. The owner and I removed the fairing between the vertical and horizontal stabilizer which revealed the top section of the horizontal stabilizer. This is the section that produces the oil can sound. No cracks, fractures, loose or broken rivets. I think the “00432160 reinforcement will solve this problem. Where does it go, would you have a picture and where can I get one?
Also took a another look at the struts stamped numbers at the base. The pictures aren’t the best but you can see a “R & L” stamped on the weld. The “L” is a little tough to see but I’m sure that’s what it is. The A&P is still not convinced about the tension of the rear spare and even went further saying it (left rear spar) had excessive vibration when the engine is at idle. This is new to me since he didn’t point this information out earlier and I didn’t see it. Any comments here?
Thx Johne

[6597]

Your IA should have a borescope to see if the stab reinforcements are already there, it's a ton of work to install them so make sure you don't already have them. I think I got mine from Univair years ago. See my previous pic as to their orientation. I'm going to presume your IA has gone thru all the Service letters and AD's regarding the tailfeathers and all check out (see Resources tab on main website page). My stab rebuild by Tim Mix in Oregon worked well for me.

I would have some experienced eyes look at the canning to see if it really is an issue.

Good news about having the correct struts. Can't help much on the rear strut, here's what my fabric wing connection looks like on the left side. Does he hear a drag wire vibrating? Much discussion on whether they were left in or out on various metalizations.

If you are a member you an access a list of more experienced mechanics on our website who may be able to shed some light. The list is by state.

[6643]

The lift struts are not under any tension while the plane is sitting stationary on the ground, in fact, they are under compression (so there won't be any tension.) The jury struts help the lift struts support that compression loading.

Likewise, bear in mind that the rear stabilizer is loaded opposite the wing, so, pulling up on the tip is not representative of the loading when the plane is in flight.

[johne]

I must admit I’m a little jealous on the condition of the spare and ribs photo. Very nice!
Sorry I didn’t pick up on photo of the reinforcement pieces earlier. I was looking at the wing they were sitting on instead of the pieces. Attached is a partial shot my empennage. I think the leading edge reinforcement is incorporated in my tail surface.
This is all really great information which just confirms I need a new A&P. He’s good but he just isn’t familiar with old airplanes. I think the last straw was when he told me I needed to rebuild my Stromberg carburetor. With the mixture control pulled back/ off, it didn’t shut off the engine and he didn’t like that either. It’s just the way things were done back in the day.
Thanks all!