strut inspection on aircraft?

[M Towsley]

Re: strut inspection on aircraft?

Larry,

Thanks for the info. Did you take off the wheels or did you need to block them to keep it from moving, or not? I take it you pad the lift, with what and how? Did you raise the tail or just tilt the drywall jack? This is great info, that 's why I wish there were more pictures and a how-to. Again, thanks for the ideas!

[Larry Lyons]

Re: strut inspection on aircraft?

Well, for the 150 she was sitting on the nose gear so no problem. As for padding, what ever you have on top of a piece of plywood, we used foam, and yes the wheels were chocked well. As for tilting the lift I have not used it for my T yet but if you were not removing the wing either way would work. However if the wing is coming off I would want the plane level so as to not put any undue stress on the attach points. Larry

[M Towsley]

Re: strut inspection on aircraft?

Larry,

I was talking about the wheels on the lift itself. I would assume you would lift the tail, put the lift under the wings, remove the struts, etc. You would need two of these to remove both sets of struts. So I take it you cut plywood to fit inside the arms of the lift? I am not sure what those look like, I will have to look at one to see. Thanks!

[jmvolpp]

Re: strut inspection on aircraft?

Here are a couple pix I dug out from the first time the struts were inspected. We repeated the same operation this fall, but didn't take more pix. However, in a day or two, will come up with a written description of the effort, and post for the record.

Mike V.

[Craig]

Re: strut inspection on aircraft?

When I removed my struts in September I raised and supported the tail so the aircraft was level. Once the struts were removed I found that 6' stepladders did the trick to support the wings. Used pieces of old carpet to cushion the fabric.

The SB has installation instructions for reinstalling them. Also, the website for the Alaska Struts also has a good procedure for installing the struts.

http://www.airframesalaska.com/tcaftinstall.pdf

Craig

[M Towsley]

Re: strut inspection on aircraft?

Thanks guys.

Mike, any close-ups of the wing supports? Looks kind of neat and easy to store when done. Why did you remove the wingroot fairings? Thanks.

[jim cooper]

Re: strut inspection on aircraft?

Mention was made of "other ways besides xrays to conform to the FAA directive" I am curious as to what these other "approved methods" are. The fellow who rebuilt my BC12D, took the struts off, put them in his pickup and drove three hours to the inspection station. Then, after they were xrayed and approved, he drove three hours back home. Did he waste alot of time for nothing?JC

[jmvolpp]

Re: strut inspection on aircraft?

Marty, I can't remember why the wing root fairings were loose at the 2007 inspection, but it wouldn't have been related to the strut removal. Attached are pix of one of the wing stands, given to me by a fellow pilot who had made them originally to be used as temporary struts during construction of one of his Pietenpols. They appear to be conduit of about 3/4" ID with all-thread inserts drilled for bolt holes. The 4" X 10'4" PVC with screw-in end plugs, on the floor, is one of the two used for transport of the struts.

Jim, while AD 2008-040-09 allows for either ultrasound or X-ray inspection, the technician that did mine (search Hoosier Aircraft Accessories on this forum) thought ultrasound to be more accurate. The size of the probe used would seem to lend itself to inspection without strut removal, but would be a little awkward for the bottom.

Overall, the 2007 AD compliance was more extensive than 2011 as it was the first time, and included:
1. Thorough cleanup, strip, inspection, and repaint of the fuselage wing attach fittings, preceding
SB 2007-02, later to become AD 2008-09-18. Inspection required fabric to be removed that had been
wrapped around the gussets, a common practice during recovering, and a contributing factor to the crash
of the floatplane that brought this whole thing upon us to begin with.
2. Fabricating and painting fairings to cover the fuselage wing attach fittings area.
3. Stripping/repainting of the lift struts. The inspector had stripped the lower 18" of each strut due to some
bubbled paint, in accordance with the AD. That was not necessary for the 2011 inspection.

For the 2011 strut removal, the aircraft was positioned with mains chocked and tailwheel placed on sawhorse as depicted in the 2007 pix. The wing stands are measured and readied beneath each outboard strut end, as is a stool or equivalent to hold the front strut when you let it down. Take care not to bend the flanges during this whole exercise.
1. Remove gear attach fairings, detach jury struts, and remove nuts from all wing attach bolts. Put all this stuff somewhere it can be found later; replace anything that's not worthy of reuse. Bolts can be backed out some before you or your associate lifts the wing to remove them.
2. Place your hands under a rib toward the wing tip and elevate the wing enough to allow the outboard bolts to be removed and the struts (rear first) to (carefully) swing down to the ground (rear) and the stool (front). Now put the wingstand in place.
3. Back the inboard bolt out enough to remove the rear strut and set aside, then the front strut.
4. Move the stool to the other side and repeat.
5. Identify the struts (I etched mine on the bottom end flats) and remove the adjustment plugs from the rear struts after noting their position, then mark each as L or R. Noting the position is best done by measurement/digital photo as it will be a lot of turns to count. Put them in the same safe place with the other stuff to be used again.
6. Upon successful inspection, apply your favorite corrosion inhibitor (I used LPS3) to each strut. Start with eye and hand protection and expect a bit of a mess. Remember that as the inhibitor, heated to make it flow better, is infused, the hole at the opposite end needs to remain open until the whole quart is inside. So as not have it immediately run back out, have said hole on the high side. Then tape over both holes to slosh it around. Remove the tapes and prop the struts up overnight to drain. "Gunk" engine cleaner is good for LPS3 cleanup.
7. Apply a little anti-seize to the adjustment plug threads before replacing them, and reverse the removal procedure to reattach the struts - a little light grease on the strut ends will help to position them into the attach fittings. Note the front strut will hold the wing by itself, if needed temporarily.
8. Button up the fairings and you're ready to go another 4 years! Keep the drain holes open and expect to wipe off more of the corrosion inhibitor for a while as it continues to ooze out, run down the gear leg, and blow down the bottom of the fuselage.

Mike V.

[M Towsley]

Re: strut inspection on aircraft?

Mike,

Thanks for the info, that helps a lot. How did the all-thread go into the conduit? I am assuming this thing is adjustable up and down? The other end is bolted to a board, then? Again, thanks!!!

[jmvolpp]

Re: strut inspection on aircraft?

Yes, they are adjustable, but I don't know whether the threads are cut or pressed into the conduit. The bottom ends stand in holes cut halfway through the 2x4.

Mike

[M Towsley]

Re: strut inspection on aircraft?

Mike,

PM sent your way. Thanks.

[fearofpavement]

Re: strut inspection on aircraft?

Mention was made of "other ways besides xrays to conform to the FAA directive" I am curious as to what these other "approved methods" are. The fellow who rebuilt my BC12D, took the struts off, put them in his pickup and drove three hours to the inspection station. Then, after they were xrayed and approved, he drove three hours back home. Did he waste alot of time for nothing?JC

The two acceptable inspection methods are ultrasonic inspection or x-ray. It has to go to a certified test facility either way, so unless there was an ultrasonic inspection facility close by and he drove a long ways for x-ray, then likely the drive was required either way. I would expect the inspection costs to be the same...

[Marv]

Re: strut inspection on aircraft?

Why not have them inspected and sealed and be done with it. seems like it would be better than tearing the airplane down every few years. It will only be a matter of time before something gets damaged taking it apart and putting it back. Eventualy you will have enough in inspecting that you could have paid for them being sealed. I think Wag Aero does this without robbing youj. Marv

[M Towsley]

Re: strut inspection on aircraft?

Marv,

I think part of the problem is cost for some, and transport issues.

I know if you buy new, you could go 40 years of inspections based on cost before you broke even. Obviously a lot less for inspection and sealed by Wag Aero.

The other issue is shipping. Expensive and hard to package for safe shipping. A lot of guys have local, or close to local, businesses where they can drive them, have them inspected and drive them back home.

It is a toss up for me, I may change my mind after I do it once.

[M Towsley]

Re: strut inspection on aircraft?

Hi all,

I wanted to resurrect this thread briefly.

When one uses the ladders under the wings method, (with padding), is it better to do it closer into the strut mounts or farther out toward the wing tip?

Should you pad between the wing ribs or on a rib?

And finally, what is the preferred method and product for oiling the struts? It looks like mine dripped out black or brown fluid after the last time it was done, but I am not sure what that product would have been.

Thanks!!!