Strut Airworthiness Directive (AD) (merged VI)

[lfries]

Re: Strut Airworthiness Directive (AD)

I just posted comments on the govt. web site. Used the closed thread to find the site. I'm not an IA or an A&P but my IA knows tube and fabric aircraft and I know he wouldn't let me fly if my struts were suspect. Until the latest incident I hadn't heard of a Taylorcraft Wing seperation.
Its too bad that the FAA isn't mandated to prerform work at there projected cost of $400 per AC. I could manage that cost every two years.
Just started teaching my Grandson to fly. Now I can see being grounded after Nov. 20 if the FAA isn't more reasonable. I would buy sealed struts, from anyone but the factory, if delivery isn't months away. In a few years the added value might make them an investment. We have a local shop that works on Kiing Airs. Based on some comments perhaps they will be of assistance in getting the inspection done. What do the King Airs need that would use the same eq. as our lift strut inspection.

[Gary Snell]

Re: Strut Airworthiness Directive (AD)

One serious flaw with this AD is the frequency of the NDT inspections. If the struts pass inspection and then are internally coated with linseed oil or other preservative per the AD, why should it need to be redone in 24 mos?? A majority of the struts are 60-70 years old and haven't been NDT'd. I would think a 5 or 10 year interval would be more reasonable. This recurring cost and hassle factor is obviously a factory incentive to throw in the towel and pay the 3500 bucks.

[astjp2]

Re: Strut Airworthiness Directive (AD)

Dont assume anything, the AD does not specify to look that the fuselage attach fittings then it is not required....period! It would be wise as an owner or operator to look but it is NOT part of the AD. Tim

[Guest]

Re: Strut Airworthiness Directive (AD)

One serious flaw with this AD is the frequency of the NDT inspections. If the struts pass inspection and then are internally coated with linseed oil or other preservative per the AD, why should it need to be redone in 24 mos?? A majority of the struts are 60-70 years old and haven't been NDT'd. I would think a 5 or 10 year interval would be more reasonable. This recurring cost and hassle factor is obviously a factory incentive to throw in the towel and pay the 3500 bucks.

Univair- $2800

Interesting, about 1800 planes and about $2800 each (worst case cost scenerio, best case revenue scenerio) comes out to about $5 million.

[whake]

Re: Strut Airworthiness Directive (AD)

I talked to a local IA who has lots of experience and incidently is rebuilding a Cub basket case, doing a perfect job. He offered me the equipment and help to do the Piper test. Which I will do. I think this should be the initial field test to see the extent of the problem. I believe my plane has original struts, the plane was rebuilt in 1990 and has been hangared the last twelve years, visually they look good. Internally is the big guess. How can you tell if they are vented or sealed? What is the standard wall thicknes of the struts? I am willing to pay $3000 for a new set. What is your guess on man hours to replace four struts???

[Guest]

Re: Strut Airworthiness Directive (AD)

I talked to a local IA who has lots of experience and incidently is rebuilding a Cub basket case, doing a perfect job. He offered me the equipment and help to do the Piper test. Which I will do. I think this should be the initial field test to see the extent of the problem. I believe my plane has original struts, the plane was rebuilt in 1990 and has been hangared the last twelve years, visually they look good. Internally is the big guess. How can you tell if they are vented or sealed? What is the standard wall thicknes of the struts? I am willing to pay $3000 for a new set. What is your guess on man hours to replace four struts???

2 hours if they are painted when you start and you have the straps for the jury struts attachements with you.

The straps are made to fit the size tubing that the struts are made of. I have a bunch of different size ones in a box 575 miles away! That's annoying!

Guess I'll make some new ones.

[Guest]

Re: Strut Airworthiness Directive (AD)

I talked to a local IA who has lots of experience and incidently is rebuilding a Cub basket case, doing a perfect job. He offered me the equipment and help to do the Piper test. Which I will do. I think this should be the initial field test to see the extent of the problem. I believe my plane has original struts, the plane was rebuilt in 1990 and has been hangared the last twelve years, visually they look good. Internally is the big guess. How can you tell if they are vented or sealed? What is the standard wall thicknes of the struts? I am willing to pay $3000 for a new set. What is your guess on man hours to replace four struts???

Vented struts have a small hole drilled in the trailing edge about a 1/2" from the bottom.

I recall .049" wall thickness

[LostnSpace]

Re: Strut Airworthiness Directive (AD)

found a place in Atlanta that does NDT for aircraft, 4 hour min. @ $85/ hour, I asked if he could do 8 struts in the same 4 hour block, he said no the price would go up a littl e bit, so it looks like $340 plus the take-off and put-on time, well below the $3495, as long as they check out good, see what happens. LNS.

[Tom G]

Re: Strut Airworthiness Directive (AD)

It doesn't get any more serious than this and I really don't have a problem with it and figure in the long run the most economical way to deal with this is to simply replace the struts with new ones. That of course depends on the cost of the inspection that is required every two years if they pass inspection now. Indications that I've heard make buying the new struts the far better idea.

What I am concerned about is a source for the struts. My right rear strut was replaced in 2001 with a Univair sealed strut. Right now from what I understand that strut doesn't cut it with this AD. I really can't make sense out of that. I'd have no problem replacing the other three, but if I do that, will I have to subject the one strut to repeated inspections? If I understand the AD it appears that I will.

These airplanes have flown for over 60 years without any strut failures but now a 7 year old sealed strut is subject to an expensive inspection every few years. Don't get me wrong I'd rather error on the side of caution but I hope some thought is given to this.

It seems to me that Univair could and should be an alternative source to Taylorcraft for these struts. I have no problem with Taylorcraft but it seems that when all of this shakes out there is going to be a huge backlog of orders for struts and a lot of grounded airplanes. Even with two suppliers this could happen.

The other source for concern is the strut attach fitting that failed on Dave Wiley's airplane. Can we expect to hear something on this as well?

If I've misunderstood anything here maybe someone can set me straight.

Thanks,

[Guest]

Re: Strut Airworthiness Directive (AD)

It doesn't get any more serious than this and I really don't have a problem with it and figure in the long run the most economical way to deal with this is to simply replace the struts with new ones. That of course depends on the cost of the inspection that is required every two years if they pass inspection now. Indications that I've heard make buying the new struts the far better idea.

What I am concerned about is a source for the struts. My right rear strut was replaced in 2001 with a Univair sealed strut. Right now from what I understand that strut doesn't cut it with this AD. I really can't make sense out of that. I'd have no problem replacing the other three, but if I do that, will I have to subject the one strut to repeated inspections? If I understand the AD it appears that I will.

These airplanes have flown for over 60 years without any strut failures but now a 7 year old sealed strut is subject to an expensive inspection every few years. Don't get me wrong I'd rather error on the side of caution but I hope some thought is given to this.

It seems to me that Univair could and should be an alternative source to Taylorcraft for these struts. I have no problem with Taylorcraft but it seems that when all of this shakes out there is going to be a huge backlog of orders for struts and a lot of grounded airplanes. Even with two suppliers this could happen.

The other source for concern is the strut attach fitting that failed on Dave Wiley's airplane. Can we expect to hear something on this as well?
If I've misunderstood anything here maybe someone can set me straight.

Thanks,

Hi Tom

I am commenting on phrases in red above. The Univair strut does meet the requirement of the AD.

Look in my prior posts and you will see there is a second AD in process that will very likely be released and involves the fittings.

The FAA folks are smart folks.

Dave

[DannyDot]

Re: Strut Airworthiness Directive (AD)

My mechanic is looking into the AD. He tells me the AD only calls out for eddy current inspection of the front struts. Is this a typo in the AD?

If there is a second AD on the way to inspect the fitting, I think waiting until it is out would be a good idea. I would hate to have to pull the struts off again in a couple of weeks/months to comply with a second AD. Anybody made any contact with the FAA on the second AD?

Danny Deger

[Ragwing nut]

Re: Strut Airworthiness Directive (AD)

My mechanic is looking into the AD. He tells me the AD only calls out for eddy current inspection of the front struts. Is this a typo in the AD?

If there is a second AD on the way to inspect the fitting, I think waiting until it is out would be a good idea. I would hate to have to pull the struts off again in a couple of weeks/months to comply with a second AD. Anybody made any contact with the FAA on the second AD?

Danny Deger

Have him read it again. It says front and AFT lift struts.

Mike

[Winston L.]

Re: Strut Airworthiness Directive (AD)

I would say that the Univair struts are equivelant. Even if you consider it an alternate means of compliance I am sure the FAA would agree that the Univair struts are equivelant.

[VictorBravo]

Re: Strut Airworthiness Directive (AD)

Does anyone know how the fuselage attach point would be inspected on an existing flyable airplane? It's one thing to remove the struts and take them to a shop for an Eddy Current. It's another thing to find a shop that can come out to your hangar and put a machine of some type up against the side of your airplane.

Like I said before, Forum member L-2 Gary had previously arranged for a mobile X-ray that would come out and take a picture of the lower strut and fuselage attach area in one film. That seemed to be reasonable to me but Dave (or someone else) mentioned that X-ray has some limitations on wall thickness.

Does Eddy Current or Ultrasound tell you the wall thickness down to a few thousandths better than X-ray? I always thought airliners had mobile X-ray come out and take pictures of the spars on heavy maintenance checks.

If the factory convinces the FAA to issue an AD and the only method of compliance is to buy a new fuselage from Harry, I can no longer guarantee his personal safety !

[whake]

Re: Strut Airworthiness Directive (AD)

As I understand, Eddy current or Ultra sound inspection will only detect cracks and wiil not tell you any thing about internal corrosion.. any experts out there ?? Also if it passes inspection I would like to see a longer interval for inspections like three to five years.