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**Forrest Barber** · 08-13-2007, 14:37

Re: Strut Airworthiness Directive (AD)

Thank you Robert! I am back on the ground. Quick check out of a TW guy. Okay now I do not consider any comments trivial or unnecessary, lets now try to read completely and then comment. I personally feel we can adequately inspect our struts with other than a very expensive process.
A few of us discussed this completely at the Type Club Tent at AirVenture.
Taylorcraft never had "sealed struts" . If you have them they are a recent purchase. I really do not want to post my ideas right now, I want to listen a bit, The Piper Strut AD and the graph paper method seems to be applicable here. THEN of course some corroded struts will be found and yes I will replace mine if found to be even slightly weakened.
The Dave Wiley accident is a completley different thing, the complete strut end attach fitting to the fuselage just pulled out , it was very rusty
( corroded). IF your strut attach fittings & struts are suspected of being corroded, salt air, water soaked, mis treatment, severe overload, what ever, USE common sense and inspect them.

**DanBrown** · 08-13-2007, 16:42

Re: Strut Airworthiness Directive (AD)

Thanks to Rob for the thread and to the tribe for all the great information.

I work part time (2 or 3 days/week) in the DOT building called out for hand delivery of comments. So I'd be happy to deliver any comments the tribe sends to me or posts here for hand delivery.

I do design and implementation of budget forecasting software for DOT HQ -- not terribly interesting, but it does allow me to afford my T-Craft and other travel.

I have an annual due in October -- It would be good to do the Part 2 inspection on my ship then (Assuming the initial visual checks out). If my local shop can't do it, does anyone know of good locations to accomplish both the annual and the eddy current or ultrasound inspection? I'd fly within a moderate distance to get it done. (Like out to Alliance if Forest can do it)

**Frank DeBartolo** · 08-13-2007, 18:51

Re: Strut Airworthiness Directive (AD)

How about the punch test?? As I understand this AD, it is still evolving and can be modified pursuant to comments and further consideration by the federales. Is it possible that if the feds received enough comments, that the comments could result in a similar punch test as the Piper AD? This would be a lot less expensive to do and might not involve removal of the struts from the airplane. The way I see the Ultra sound and eddy current test, it appears to be expensive due to certified technicians and specialized equipment and labor intensive due to disassembly of the wings in order to remove the struts. If a strut or struts were to fail, strut or struts still have to be purchased--all this after the cost of the expensive test. The best way to go then is belly up to the bar and buy new struts. However, the punch test, especially if struts do not have to be removed would be the most cost effective way to go.

Frank D

**Guest** · 08-13-2007, 18:53

Re: Strut Airworthiness Directive (AD)

I made this comment on one of the "closed" threads that preceeds this one.

I am looking for comments and thoughts.

I talked with my FSDO about starting a repair station solely for the purpose of accomplishing this inspection. Based on a conversation he thinks it very do-able and one could perform the inspections in the feild as well as in the shop.

That has value because as an I/A starting a repair station I think you side step all the employer level II and level III certification which is the best I can tell merely a way to certify and train employees "off the street" rather than an A&P or I/A.

If one considers how big a radius one might serve due to how far he or the a/c might practically travel and how many airplanes "live" within that circle you could know whether its financially worth the investment in the repair station. ie if there are only 6 planes within that circle then 6 inspections every 24 months may not be worth it.

The actual ultra-sonic thickness test can't be more than hour or two so it should be less than $150 or about $75/year strut removal will add to that.

I also wondered about making a stock pile of pre-inspected used struts for swap out.

Just brainstorming, any thoughts?

**Forrest Barber** · 08-13-2007, 19:10

Re: Strut Airworthiness Directive (AD)

Gosh I like brain storming.... I too agree that the Maule test method is the answer , along with another trick many have used before that was kicked about at Airventure.

The Taylorcraft strut lends itself to a very easy method of inspection in that the lower end "plate" for lack of a better word can be cut and peeled back or just cut off, it is off the neutral axis and then you can LOOK up into the stut for corrosion, IF none then swab out, treat and reweld.

We have a few struts here cut open for inspection at the Fly-Ins....
keep brainstorming I am going to turn up the AC in the bedroom and call it a 15 hour day to this point . I will wake up at 6:30AM to a cup of "proper" English tea and some marmalade. Goodnight Bob, Ruthie & Tuck.....

**N96337** · 08-13-2007, 19:21

Re: Strut Airworthiness Directive (AD)

Originally posted by drude View Post

The actual ultra-sonic thickness test can't be more than hour or two so it should be less than $150 or about $75/year strut removal will add to that.

I also wondered about making a stock pile of pre-inspected used struts for swap out.

I talked to our prop shop guy today, about this very thing. From what he said, you're right on track with cost... and that's a whole bunch cheaper than replacing struts to line someone's pockets if your struts are good already. He also suggested the swapping of struts that are already inspected and I'm all for that as well, although he was more suggesting that there be one set "floating" around to use while your struts are getting inspected if you have to send them away. He also said that his eddy current guy goes around quite often to other areas to do inspections on Lears (I don't know just what needs eddy current on them, but they seem to be scattered around the country pretty well) and if a few of us came there, it would have an impact on cost per strut. The guy could set up and do a bunch at one time, all off, clean and ready to inspect.
With that said, I never had much faith in the Maule tester on a strut. My feeling was that if it was far enough gone to let that dent it, it was WAY too far gone to fly. I agree with Forrest that the very best would be to pull the small patch on the bottom and visually inspect... and I'm going to bet that there aren't many found that are bad.
JH

**flybikefarm** · 08-13-2007, 19:29

Re: Strut Airworthiness Directive (AD)

My IA said there is a place in Rockford Il.that does testing on the Kingair he maintains. That would be convienent for several of us here in northern Il.. George

**TCTOM** · 08-13-2007, 21:44

Re: Strut Airworthiness Directive (AD)

Reference http://www.weaplane.org/igi-bin/forum

Unfortunate incident and loss of a great aviator!

**VictorBravo** · 08-13-2007, 23:06

Re: Strut Airworthiness Directive (AD)

On the first read-through when the AD text was posted in a forum message, it was not easy for me to fully understand the exact steps to be taken or what is an alternative to what. I felt like a layman trying to make sense of a legal contract written by a team of lawyers on acid.

Can one of the experienced IA's on the group "distill" and simplify the AD into basic terms that are more easily digestible? I think it would be a good service to the group. If I understood it I'd be glad to write out the Cliff's Notes version myself, but it appears I'm one of the unwashed and uneducated masses that has trouble grasping what the AD is actually telling you to do.

Much as I normally enjoy skewering the nice folks in Brownsville, does anyone know if there is indeed some number of old Taylorcrafts that have corrosion problems in the lower struts? Has anyone on the group looked at NTSB or FAA data and found that there is an increasing number of strut failures or service difficulties? Even Mussolini was right about a couple of things, the trains didn't run on time and he managed to fix it

drude, yes I now see that the Wiley tragedy and the AD are separate issues, even though the underlying issue is similar. So it would seem to be wise if we as a group figured out whether in fact the first one of the AD's is bogus or not, and then whether to support either or both of the AD's.

Bill

**VictorBravo** · 08-13-2007, 23:12

Re: Strut Airworthiness Directive (AD)

Originally posted by N96337 View Post

With that said, I never had much faith in the Maule tester on a strut. My feeling was that if it was far enough gone to let that dent it, it was WAY too far gone to fly.

I agree with Forrest that the very best would be to pull the small patch on the bottom and visually inspect... and I'm going to bet that there aren't many found that are bad.
JH

I also suspect that a failed Piper style Maule test means it has already gone too far.

What about drilling and tapping a hole in the area where the "patch" is, allowing you to insert a borescope for a full visual inspection, spraying corrosion preventative through the hole, then screwing in a bolt or set screw with Permatex sealant to keep it closed between inspections?

**astjp2** · 08-14-2007, 00:51

Re: Strut Airworthiness Directive (AD)

Well the short and skinny on the ad is visually check all of the lower 12" of the struts and then to either remove them and NDI the strut every 24 months or replace them with sealed ones. The Maule fabric was not allowed in this AD. There is the alternate method of compliance that can be applied for to use the Maule fabric tester but the FSDO would have to approve it. Most of the mumbo jumbo is the certification level requirements for the NDI tech doing the inspection. Tim

**M Towsley** · 08-14-2007, 04:35

Re: Strut Airworthiness Directive (AD)

Forrest,

Perhaps you could clarify, or it may be too early to do so regarding the 'D' models. My L-2B, (parts ship except for the genuine throttle), appears to have sealed struts. Don't know the manufacturer, it was completely redone in 1993 by Mr. Johnson. I know this does not affect me 'officially', yet, but will it due to my sealed struts? Thanks.

**Dick Huish** · 08-14-2007, 05:32

Re: Strut Airworthiness Directive (AD)

Marty, I have run into them before. I haven't figured out when they closed the bottom, but I haven't seen many and having seen a lot over the years I don't even remember what ships they were on. Dick

**Guest** · 08-14-2007, 06:05

Re: Strut Airworthiness Directive (AD)

Originally posted by VictorBravo View Post

I also suspect that a failed Piper style Maule test means it has already gone too far.

What about drilling and tapping a hole in the area where the "patch" is, allowing you to insert a borescope for a full visual inspection, spraying corrosion preventative through the hole, then screwing in a bolt or set screw with Permatex sealant to keep it closed between inspections?

I discussed that with the engineer and in the process I convinced myself that I will not be able to discern the wall thickness with that method. Old rust and linseed oild mixed will make it too hard fo me.

I think its somewhat bogus. The engineer says the factory showed them corroded struts and that Forrest said he saw some too that were so rusty he could push his thumb thru.

But the reason I call it bogus is that I don't know pedigree of said struts. Were the laying in wet ground for years or on an airplane? I think that's important to know. But on other the hand I don't have to wait till one of us guys dies to figure out that this should be checked in some way.

Hey Forrest if you have issues with what I just wrote talk to Andy not me that's what he said.

Dave

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