Strut Airworthiness Directive (AD) (merged VI)

[gilligansae]

Re: Strut Airworthiness Directive (AD) (merged III)

This is a truly an emotional thread- and I have waited a couple of days to try and be really objective. I have been doing my homework and know the following:

1. The struts are expensive (~3k including disassembly, paint, reassembly)
2. The strut availability is going to be very scarce (if it isn't already)
3. There is no way the factory or Univair is going to get all the strut made for all of us in a short period of time (3 months) assuming all of us just buy new ones because of the following:

4. I have called no less than 4 NDT facilities in the Western New York area.
All of them have told me the same thing.....

5. Eddy current inspection is not used and doesn't work on steel tubing- it is ideal for aluminum

6. Ultrasound is great but almost nobody does .020- .060 (I may not be quoting the SB accurately) thick as specified

7. It is not perfectly clear if the inspector has to be FAA approved to sign the log, or if the inspector publishes a report for the IA/ AP to approve and sign off

8. None of the FAA repair stations I have spoke to so far in WNY area know how to or where to get eddy current/ ultrasound inspection done.

9. Many of us are freaking out about this.

Either way it looks like a great many of us will be essentially grounded until we can find an inspection service, afford new struts, wait until these struts exist, or find an alternate method of compliance!

Please comment. I will post the same comment on the AD thread.

Jeff LaChausse
1946 BC12-D

[Richard Boyer]

Re: FAA Airworthiness Concern Sheet

again, I'm confused.......

the 3 month term is being used again.......When I read the AD, it says within the next 5 hours after Aug 20.

I don't know about you guys, but that isn't much time.....

What is 3 months? (I'm sure I missed something.....)

[Ragwing nut]

Re: FAA Airworthiness Concern Sheet

again, I'm confused.......

the 3 month term is being used again.......When I read the AD, it says within the next 5 hours after Aug 20.

I don't know about you guys, but that isn't much time.....

What is 3 months? (I'm sure I missed something.....)

5 hours to make a visual inspection, 90 days from August 20 to get the eddy current done.

[Richard Boyer]

Re: FAA Airworthiness Concern Sheet

Ah!!!

thanks!

Well, I visually inspected my 7 year old struts and they are still perfect........

[flyguy]

Re: Strut Airworthiness Directive (AD) (merged III)

Jeff,
Yep. Probably.
DC

[astjp2]

Re: Strut Airworthiness Directive (AD) (merged III)

[QUOTE=Ragwing nut;32451]I will be building a clipwing Swick/Cole is the reason why I will be going experimental.

astpj2:
Airworthy is not defined by the FAA. Not even in FAR 1.


Take a look at FAR 3.5.a, you will find the definition of airworthy.

As for the lycoming engine, converted to a Tim engine, I have an O-290 crank put into any O-360 case and use a custom ground cam of my design and I rate the engine as a 345 ci and 175 HP, and I put my own data plate on the engine, the engine is of my own experimental design then the ADs for the lycoming would NOT apply to MY engine....Tim

[Dano"T"]

Re: FAA Airworthiness Concern Sheet

Mike,

I'm sorry but that is a poor argument....... First, are all taylorcraft struts like the Piper struts? This AD address ALL struts over 2 years old on all models. Also, there are LOTS of things on airplanes that if they broke someone is going to get killed. This AD does not make sense. My struts are 7 years old. Thats it. But according to this AD, they are unsafe and I may be killed.

Horse hooey.

When the FAA comes out with a new AD, it should be based on SOUND scientific data and consistent with past precedent. I am not convinced that is happening in this case. I am willing to tests my struts at annual time, with the maule punch test. It is easy, non destructive and fairly painless in its procedure (although my IA says I will have to buy a punch, because testing it on the strut is hard on the tool).

Amen BROTHER! If there are crappy parts that passed inspections....issue an AD against crappy IA's....the system works NOW. IT AIN'T BROKE SO DON'T FRIGGIN FIX IT. Also the thing that erks me is no on plane testing....the struts must be removed.....so the FAA is so unsure of the test and it's ability to detect corrosion that you must remove your struts so you can here the weld scale and spatter rattle around while your dancing with delight at how the FAA has saved us all from a problem that really doesn't exist....this can easly be taken care of at annual by our IA.....Like it always has. How many of these rust bastards struts were actually removed from a flying airplane.....and if they were....more proof that the system works.

[DannyDot]

Re: Strut Airworthiness Directive (AD)

The absence of vent holes alone does not make them sealed neither does the welding.

They have to have been coated with linseed oil or equiv. when manufactured and also they need to be sealed at the bolt hole locations.

Look at the rear strut- is the adjusting tube hollow or does it have a cap welded on the end so it looks solid? Hollow means not sealed.

Take the top bolt out the front strut, look in the strut bolt hole. Is it a straight thru hole thru a sleeve or can you access the middle of the strut tubing from the bolt hole, ie no sleeve around the bolt. If you can access the tubing center from the hole its not sealed. Use a pice of safety wire as a test probe.

I bought my plane a couple of months ago. It was rebuilt in 2006, but very little paperwork as generated. It is possible sealed struts were installed but not noted in the log. If my mechanic does the above tests and finds the struts to be sealed, can this be noted in the log book? I would hate to have him drill holes in a sealed strut to get the oil in. This brings up the question, is putting oil in the strut part of the AD?

Danny Deger

[NY86]

Re: Strut Airworthiness Directive (AD)

If my mechanic does the above tests and finds the struts to be sealed, can this be noted in the log book?

If you brought your plane to me I'd first check for sealed struts. If they are all sealed (and approved), I'd write in the logs that the AD does not apply and no further action is required as long as the struts are not replaced.

[Guest]

Re: Strut Airworthiness Directive (AD) (merged III)

Hey Danny,

I made a mistake in that post you quoted above.

I left out that the rear strut can be sealed by capping the bottom end of the internally threaded tube.

Test that by pushing a rod or long screw driver or such down the open top end of the rear strut. If it is stopped after going in 4 or 5 inches the it is sealed on the top end.

If I was looking at your struts and it passed the test above, no drain holes and had a thru bushing at the top of the front strut, then I would look for FAA/PMA stamps on the ends near the bolt holes.

If I found something that could be traced back to Univair (most likley supplier) then I would consider it complied with.

Also you could call the rebuilder ask him where he got them and do back tracking.

Dave.

[VictorBravo]

Re: Failed Struts

The AD addresses struts that are simlilar in construction to Piper struts

Congratulations, Mr. Rice, by your being the only one to come forth (thank you sincerely), you are now the de facto representative for the current "factory" here on the front lines of this debate... sit down and make yourself comfortable

Question 1: Your post's first line re-iterates what we all know, that the Taylorcraft struts are similar to the Piper struts. Other than for the purposes of fear-mongering and making an immediate profit, WHY would the factory Service Bulletin and the subsequent AD not allow the same type of inspection that has proven to be acceptable and safe on Piper airplanes?

Question 2: It has been pointed out by reasonably experienced and competent experts that the Eddy Current inspection is good for aluminum but not good for steel tubes. WHY does the factory SB and the subsequent AD insist on Eddy Current?

Question 3: It has been pointed out by reasonably experienced and competent experts that X-ray will give a superior, safer indication of the state of corrosion within a thin-wall tubular aircraft structure and weldments. WHY does the factory SB and subsequent AD disallow the use of an X-ray inspection?

Please provide direct answers to the above questions, without any side-stepping or spin. By doing so you will be helping earn some credibility for your organization.

I think I speak for everyone here when I say that the "factory" has an obligation to play fair in this matter, especially considering that (I backspaced over this part, even I occasionally know when to shut up).

Bill Berle

[Jose]

Re: FAA Airworthiness Concern Sheet

How do you go about replying? I checked mine with the punch test and all was good

[mikerice]

Re: FAA Airworthiness Concern Sheet

Much as I would like to present myself as an expert on corrosion and the ins and outs of writing an Airworthiness Directive, I cannot, so I can not directly answer Mr. Berles' questions. I did not write the AD.

However, as the webmaster for the Taylorcraft factory, and a previous 1946 BC12D project owner, I have closely followed the discussion regarding the struts and corrosion.

I know there are material differences in the many ways to test the struts. I cannot speak to the whys and why nots of which methods were picked, but it is obvious to most folks that the punch test, while the simplest to perform, is not an accurate test. It only tells you that the strut metal is strong enough to resist the punch. It does not indicate corrosion or lack of corrosion, and it does not measure tubing wall thickness. You cannot calculate strength without an accurate wall thickness.

There are also problems with eddy current and ultrasonic and x-ray inspections which require very knowledgeable operators and expensive equipment. Personally I favor an interior visual inspection and a micrometer for the wall thickness, but then the inspection is no longer Non Destructive Testing....

My project aircraft struts sounded horrible when flipped end for end, due to something falling inside the strut. Welding scale? Rust? I don't know, but it made me think thrice about putting those struts on a flying aircraft. To me that is a good reason to remove the struts as part of the inspection. My ear cannot measure strut wall thickness, but common sense says that does not sound right and further inspection is required. You cannot apply that common sense with the strut on the aircraft.

As for other questions regarding strut differences and why all struts are required to be inspected, I defer to the experts like Forrest that see lots of these struts. I think it would be difficult to grandfather in a 5 year old strut and not a 6 year old strut. It is probably easier to say "all struts" must be inspected.

[VictorBravo]

Re: FAA Airworthiness Concern Sheet

Much as I would like to present myself as an expert ....... I did not write the AD....

it is obvious to most folks that the punch test, while the simplest to perform, is not an accurate test.

There are also problems with eddy current and ultrasonic and x-ray inspections which require very knowledgeable operators and expensive equipment.

My ear cannot measure strut wall thickness, but common sense says that does not sound right and further inspection is required. You cannot apply that common sense with the strut on the aircraft.

But, you are the ONLY person from the "factory" to present themselves in any form. Would you be kind enough to get the factory's qualified structural engineer (who presumably WAS involved with the Service Bulletin and AD) to come forward, and answer the three thousand people who he has inconvenienced ?

Has the "simple but inaccurate" punch test proven to be satisfactory to the FAA and the safety of the owners of Piper struts... yes or no?

Yes, there are problems with Eddy Current, Ultrasonic and X-ray... the largest of which is that your company has insisted on people doing some of them without full justification or consideration.

Common sense ?!?... why in hell have you brought up that obviously foreign concept now if your company had banished it from the discussions before now?

It is more than appropriate for Taylorcraft LLC to have a presence on this discussion group, and answer the legitimate questions that are raised, and to defend its actions. Until I see different from Taylorcraft, I will say authoritatively that on this discussion group we have more engineers of all types, more engineers who have expertise pertinent to this issue, more mechanics who are experienced with these airplanes, and more owners who have the best interest of the aircraft in mind than Taylorcraft LLC has.

Some very serious (and pointed) questions have been raised by several of us here, over and over again, with no legitimate or substantive response from the company. Any legitimate aircraft manufacturer or type certificate holder would jump into the discussion, battle it out with the people who have been affected by this issue, and provide explanations for the questions that have been raised.

There has already been a public discussion, supported by more than a few people, that owners would buy replacement struts from anyone other than the factory. You would think that the factory would respond to this right here on this Forum if they wanted to salvage a scrap of credibility and have a hope of selling any parts.

Why has your company not addressed any of this?

[cpirrmann]

Re: Strut Airworthiness Directive (AD) (merged III)

Hey Danny,

I made a mistake in that post you quoted above.

I left out that the rear strut can be sealed by capping the bottom end of the internally threaded tube.

Test that by pushing a rod or long screw driver or such down the open top end of the rear strut. If it is stopped after going in 4 or 5 inches the it is sealed on the top end.

If I was looking at your struts and it passed the test above, no drain holes and had a thru bushing at the top of the front strut, then I would look for FAA/PMA stamps on the ends near the bolt holes.

If I found something that could be traced back to Univair (most likley supplier) then I would consider it complied with.

Also you could call the rebuilder ask him where he got them and do back tracking.

Dave.

This brings up a good point. Old aircraft, perhaps incomplete logs, what is the physical description of sealed struts for Tcraft? Does anyone have photos? I assume that even if they look 'sealed' the holes at the bottom nullify that.