strut inspection on aircraft?

[jim cooper]

Re: strut inspection on aircraft?

A T-Craft is one of the cheapest aircraft there is to fly and maintain. Compared to a SuperCub,Citabria, Maule,etc. its a very small investment for a lot of fun. (Gassing up a Stearman today is alot of dough!) Bite the bullet, take Hanks advise and buy the struts. Chances are your struts are 60-70 years old. Its time. JC

[Craig]

Re: strut inspection on aircraft?

Hi Marty

When I used the ladders I placed them about midway between the wing strut attachment points and the wing tip. I placed them on a rib at a location that allowed for the weight of the wing to rest on the top of the 6 foot ladders.

As for fluid I believe most used linseed oil.

[M Towsley]

Re: strut inspection on aircraft?

JC, I have no problems spending money on my plane. However, I can inspect my struts for 40 years for the cost of new and really don't want to hassle with setting up struts on a plane that flys perfectly well.

Craig, Thanks for the info! That's what I was looking for, appreciate it.

[NC36061]

Re: strut inspection on aircraft?

We recently sent a total of nine (4 front, 5 rear) struts to Wag-Aero for testing; 5 passed (2 front, 3 rear), just got them back sealed and epoxy primed, ready for another 70 years of service.

[N96290]

Re: strut inspection on aircraft?

I have 3 in to Wag-Aero (2 rear and 1 front). I have been advised of the inspection which went good and now they have to be oiled and sealed. By the logs Four years ago one of mine failed and was replaced with a Unavar strut. The other 3 passed then and I was advised before I sent them in that those which had passed four years ago were pretty likely to be able to be sealed, which they can. I just built some stands from 2 X 4 lumber and used some of the scrap 2 X 4 to make some super wheel chocks so it is not very likely to move in the hanger.

[M Towsley]

Re: strut inspection on aircraft?

I'm in the process of getting ready to pull mine and take them to Creve Coeur, MO for inspection.

[woodmw]

Re: strut inspection on aircraft?

Mine will come off soon. I have made initial contact with a guy in the area that does NDT. He says he can do the inspection. If it doesn't work out, I'll be heading to San Antonio, which wouldn't be that bad. Drop the struts off, spend the afternoon on the River Walk, or go to the National Shooting Complex for a few rounds of skeet. Life can be tough. I have a friend here that has a T-Craft project in his hangar. He is letting me borrow his struts. Plan to remove mine, use his to support wings until mine are done. That way I don't have to be as concerned about plane moving while I work on other projects, i.e. new pulleys, panel, fuel tank repair, and interior.

How much wing tip movement is allowable while struts are disconnected?

[M Towsley]

Re: strut inspection on aircraft?

Mike,

What little I know is close to none. The aileron control cables are under flight tension. Also, if the wing bands are on those wouldn't do well to be moved while installed/screwed on. Maybe others more knowledgeable on this particular item can chime in.

[jim cooper]

Re: strut inspection on aircraft?

Mike,

What little I know is close to none. The aileron control cables are under flight tension. Also, if the wing bands are on those wouldn't do well to be moved while installed/screwed on. Maybe others more knowledgeable on this particular item can chime in.

One of the AI's I know is 84-5 yrs old. He claims the" struts are VERY important to your life and they are OLD. "So replace them,,,got it?" unquote. He went on to remind me that the FAA requirement was flawed as the only one that failed was NOT the strut but the lower attach point which was on a T-Craft that had been on floats for years (high stress) and subject to ALOT of salt water corrosion. Had I kept the T-Craft I would surely bought new struts AND CAREFULLY inspected the lower attach points.(removing some fabric and really looking!) Taking the struts on and off, driving them for miles, etc. seems a waste of time and money. P.S. They do Have TO be removed, signed off, oiled and replaced. Thats the reg. JC

[M Towsley]

Re: strut inspection on aircraft?

JC,

I think this has been covered many times over. Your statement is somewhat confusing, replace your struts but it was the attach point that failed. ??? I am well aware of the very high time and experienced Taylorcraft pilot that lost his life due to corrosion of the lower strut mount on his high-time in-water float plane. I actually had the honor to speak to this gentleman not long before the crash. That being said, I personally have never heard of a strut failure. I know there were some struts at the factory that were found to have corrosion, I believe Forrest remarked on these, but no known failures. My research has not uncovered any. I am obviously open to corrections on this statement and welcome them.

My quote you highlighted had to do with the removal of struts and not allowing the wings to move during strut removal. I'm not sure what this had to do with replacing struts. You had your Taylorcraft long enough to do a strut replacement and you had a very experienced rag and tube mechanic who had the knowledge to do it. Along with the hassle of buying, painting, (along with matching 20 year old paint), setting up the struts again for the aircraft is actually finding someone in my area that can actually do it correctly. Most of these guys have little to no knowledge of how to do this. If mine ever need to be replaced, they will be. However, I choose at this time to have them inspected.

[jim cooper]

Re: strut inspection on aircraft?

It should not be "confusing" at all. The reg. is very clear as to what one must do. People still around who are knowledgeable about this inspection are numerous. It seems to me easier to have one of them paint and install a new set of struts (to satisfy the FAA once and for all) rather than worry about screwing up the airplane while trying to do it yourself over and over. Here we enter the world of diminishing returns. I never mentioned that the FAA was reasonable but rather that it WAS the law.To me buying jacks, constructing wing props, having one slip screwing up a wing to save a few bucks seems foolhardy AND confusing, BUT thats only my humble opinion. The T-Craft is a VERY inexpensive aircraft to fly and maintain. I would rather have someone really knowledgeable work on mine It gives me peace of mind in a steep turn, a radical slip on landing, etc. For me its worth it. End. JC

[M Towsley]

Re: strut inspection on aircraft?

Jim,

The reg is not confusing at all to me. Your comments are. I can understand how working on an airplane can be confusing to some people, it is not to me. Everyone knows their limitations. In this case it is just nuts and bolts, no black magic involved as long as you understand the process. Hence, asking questions on here. Even to replace the struts one has to 'construct wing props' or in this case shove a couple of padded six foot ladders under each wing. Practice makes perfect and for some folks this is the second go around since the AD. And, you don't have to explain the law to me. I enforced it for over 26 years. I am quite capable of understanding it and carrying it out. I have a capable A&P/IA that can inspect the work. I just don't have anyone that can re set-up the airplane from scratch that I trust.

[Hank Jarrett]

Re: strut inspection on aircraft?

There are two issues here. The FAA says NO CORROSION DAMAGE on the insides of open struts, NONE. As an engineer I do not consider light surface corrosion to be "damage", but most inspectors take the safe side and fail anything with any corrosion. If they use x-Ray to inspect, they won't SEE any surface rust, just pitting. Same for ultrasonic. WAG AERO drills a hole and uses a borescope to LOOK at the insides. They fail more than the NDI techniques alone will. For me, if you drill holes it isn't NDI any more, it is invasive. That isn't bad since they seal the struts that pass and make them "sealed", eliminating the inspection requirement, but they are very conservative in what they pass. (This is a GOOD thing).

As to whether the inspection is needed at all, in my opinion (worth what you pay for it) NO, because there has NEVER been a reported failed strut. NONE, NEVER, NOT A SINGLE ONE! The crash that started all of this was a failure of the lower longeron at the strut attach, NOT a strut failure. The struts the "Factory" showed (if you can call it a factory at that time) the FAA had been laying in the mud behind a building and were rusted through.

There was NO history on any of the rusted struts as to their condition on removal, but they had holes you could put fingers in. The interesting thing was, NOT ONE WAS BROKEN. I tried to get the FAA to pull test them to see if they would survive flight loads and they refused. Based on analysis of one I got pictures of they would have still taken flight loads. If the struts could be flown with VISIBLE HOLES then we should have been able to punch test the struts on the plane and saved a lot of money. The FAA went witht he factory recommendation.

That's the short history. We are stuck with this AD because the owner of the factory at the time wanted to build his capital by selling new struts (which he never sold). The FAA puts a lot of stock in a factory recommendation, even when the factory had NO ENGINEERING support. We are stuck with it. I put Wag struts on my plane (I think Wag does great work and they are very conservative in their engineering)

As for your AI saying to replace them because they are old, well I can't fault his conservative approach, but his logic is badly flawed. The whole plane is old, and so is he. We don't replace parts (or AI's) because they are old.

Hank

[M Towsley]

Re: strut inspection on aircraft?

Exactly, Hank. Many of us followed this whole debacle from the very beginning and knew what the real reason behind it was. Thousands of planes and millions of dollars in profit for replacement struts, or so it was thought by the factory owner at that time.

[Hank Jarrett]

Re: strut inspection on aircraft?

He deserved what he got, and it was good for the other suppliers of struts (who all seem to have turned out to be friends to GA). As far as I know he didn't ever sell any new struts (or even get manufacture approval) and there were some real questions about the ones that were shipped being from planes he had in for repairs. All in all, having Harry gone is one of the best things to ever happen to Taylrocraft.
Hank

Maybe we need to post his picture again so everyone will know him on sight. ;-)