Crack on A-A11 Strut Ftg

[Frisbie]

Does anyone have info they could share on repair to a cracked strut fitting? During my annual inspection I found a crack in the fwd lwr web at the weld for the gear attach point. The AD references the 43.13 for the repair but that’s a little vague for a very important piece. I would like to hear from anyone that has repaired theirs and maybe a picture for clarity?? I don't really want to replace the whole fitting and all the new stresses that may introduce.

[Forrest Barber]

Re: Crack on A-A11 Strut Ftg

Aha somebody used the B model instead of dailey discussion..... Atta boy. I tried to reply and locked up threads and created a lot of havoc with the forum.... In a nut shell , get your trusted A&P and IA to peel fabric back about a foot around the fitting. Prop wing , or remove, Pull landing gear, I would do both sides to properly comply with the AD on the fitting. Good time to do struts if they are not sealed.
Get a good Oxy-Act welder to do a repair ; it will need a big Bud and his torch combination. Check inside oif course for any corrosion , when was the strut attach fitting AD CW , It looks like a possible bad situation. Where are you located... Is it in Annual now? Your direct e-mail is here too . YES I have the fitting here for reference only ..... It is really not something that should be replaced in the field. I will send drawing direct e-mail . Too big for here.

[astjp2]

Re: Crack on A-A11 Strut Ftg

Why not Tig it? The heat affected zone is a lot smaller and less chance of warpage. Forrest, can you email me a copy of that drawing too? Thanks Tim

[Frisbie]

Re: Crack on A-A11 Strut Ftg

Looks like the fitting is going to have to go! Further inspection and discussion with the FAA seems that there is no decent way to repair. So I'm working on my 337 and run that by the FSDO before I start.

The oxyacetylene method is my personal favorite weld. That's how they were originally built and it offers a convenient way to normalize the area after the last weld.

[astjp2]

Re: Crack on A-A11 Strut Ftg

Good luck in finding one, I know of only 1 in the country and he is saving it for his airplane. Does anyone have a drawing for one that you can get it made? Tim

Looks like the fitting is going to have to go! Further inspection and discussion with the FAA seems that there is no decent way to repair. So I'm working on my 337 and run that by the FSDO before I start.

The oxyacetylene method is my personal favorite weld. That's how they were originally built and it offers a convenient way to normalize the area after the last weld.

[Frisbie]

Re: Crack on A-A11 Strut Ftg

Yes. I have the assembly drawings that show the final dimensions and Forrest Barber has copies of the detail drawings that he is forwarding to me. It's really not that complicated - it's just making that first cut is a 7 year old cover job that's going to be tough!!

[dmack]

Re: Crack on A-A11 Strut Ftg

John,

You are not alone with cracked A-A11 fittings. During our annual inspection this year, I stumbled across a linseed oil leak at the back of the fitting. I could not find the source until we had the NDT folks come out and Magniflux the joint. We have found several small cracks, including one that will not likely be able to be fixed without replacing the fitting. Have you made your components for the brackets yet? I too recieved the A-A11 fitting drawing from Forrest. I have not yet been able to get the component drawings from him. I am looking for the 4 part drawings listed in the assembly drawing. Do you have these? Would you mind passing them along?

Thanks!

Dave

[Hank Jarrett]

Re: Crack on A-A11 Strut Ftg

I now have access to a scanner that can make digital copies of drawings (not mine, they charge about a buck a scan). I plan to start scanning the drawings I have and can do the same for anyone who has the strut fitting drawings. It will be a LOT easier to send out a digital copy that can be taken to most blueprint or copy shops and printed full size!
If we can ever get a machine up to Forrest's files it would be great to make digital copies of his files!
Hank

[Frisbie]

Re: Crack on A-A11 Strut Ftg

John,

You are not alone with cracked A-A11 fittings. During our annual inspection this year, I stumbled across a linseed oil leak at the back of the fitting. I could not find the source until we had the NDT folks come out and Magniflux the joint. We have found several small cracks, including one that will not likely be able to be fixed without replacing the fitting. Have you made your components for the brackets yet? I too recieved the A-A11 fitting drawing from Forrest. I have not yet been able to get the component drawings from him. I am looking for the 4 part drawings listed in the assembly drawing. Do you have these? Would you mind passing them along?

Thanks!

Dave

My notes and dwgs are at the airport - I'm in the middle of changing the fitting out right now. I can send you my notes and dwgs but might be easier for me to e-mail them to you direct. Probably won't be back at the shop in a couple of days but I will share what I have. I'm curious if you have replaced the struts with the new sealed struts. I will try to post a few pics of my progress so far.

[dmack]

Re: Crack on A-A11 Strut Ftg

Thanks for sharing the phots John! looks like you have made good progess. Is the crack in the fourth photo what caused you to remove the bracket? Just wondering. On our plane, the brackets look good, but the 45 degree gusset plates and the wrap around weld that goeg back to the longeron have cracks.

[astjp2]

Re: Crack on A-A11 Strut Ftg

I hope you have good measurements or a fixture to put the fitting on with, if you are off just a little bit it can cause other parts of the airplane to be out of alignment. Tim

[Frisbie]

Re: Crack on A-A11 Strut Ftg

I made a fixture to locate the new fitting before I took the old fitting off. The new fitting is under primer now and may have the fabric back on tomorrow. WHEW! Answered prayers! Here are a few more pics.

[Frisbie]

Re: Crack on A-A11 Strut Ftg

Slow but forward progress on the strut fitting repair. Should start the assy process tomorrow!

[Robert Lees]

Re: Crack on A-A11 Strut Ftg

John (Frisbie):

Thanks for posting this thread with its photos.

This sort or repair would be frightening for most folks, but you seem to have grasped the mettle and got the job sorted.

I hope that I would tackle this or other problems with the gusto and confidence that you have shown.

So Bravo! to you.

Rob

[jstall]

Re: Crack on A-A11 Strut Ftg

Post moved to new thread on misaligned struts here