Strut Testing - where, who and what cost? (merged)

[Mike]

Re: Strut Testing - where, who and what cost? (merged)

Struts were on. I called them up and three hours later I had the AD compliance sticker for my log book. Attached is the letter from the FAA approving their AMOC.

How do they treat the struts with corrosion inhibitor with the struts in place?

Re: Strut Testing - where, who and what cost? (merged)

Thanks AKbrew, another question if you don't mind.

I can't read rhe print on the letter.

Can you tell me if the letter says that leaving the struts on is ok?

Thanks, Dave

[AKbrew]

Re: Strut Testing - where, who and what cost? (merged)

I forgot to mention...Alaska X-Ray also told me today they have rejected ONE out of forty struts tested so far.

[AKbrew]

Re: Strut Testing - where, who and what cost? (merged)

Struts were on. I called them up and three hours later I had the AD compliance sticker for my log book. Attached is the letter from the FAA approving their AMOC.

Re: Strut Testing - where, who and what cost? (merged)

Hello Drude,

I'll call Alaska Industrial X-Ray tomorrow and see if they will fax me a copy of the approval letter. If they send me a fax I will post it. I spoke with them today and they have been doing AD compliance x-rays on Pipers and Maules for many years, and as stated in other threads, the AD for Taylorcrafts closely mirrors the Piper AD. I asked them for confirmation they had an approval letter in hand from the FAA and he read it to me verbatim over the phone. Again, I'll see if I can get a fax copy for all to view.

Thanks, did they do it with struts on or off?

[AKbrew]

Re: Strut Testing - where, who and what cost? (merged)

Hello Drude,

I'll call Alaska Industrial X-Ray tomorrow and see if they will fax me a copy of the approval letter. If they send me a fax I will post it. I spoke with them today and they have been doing AD compliance x-rays on Pipers and Maules for many years, and as stated in other threads, the AD for Taylorcrafts closely mirrors the Piper AD. I asked them for confirmation they had an approval letter in hand from the FAA and he read it to me verbatim over the phone. Again, I'll see if I can get a fax copy for all to view.

Re: Strut Testing - where, who and what cost? (merged)

I had my struts x-rayed yesterday by Alaska Industrial X-Ray. After evaluating the x-ray they issued me the following log book entry: "X-ray inspection of the Taylorcraft Wing Struts for corrosion in compliance with A.D. 2007-16-14 and approval letter dated 9/12/07 was accomplished. No significant corrosion was found and the following struts are considered airworthy. Corrosion Inhibitor Procedure found in S.B. No. 2007-001 shall be accomplished prior to the return of service." The entry is signed by the inspector, includes the repair station ID and the inspector's certification #. This company has been doing Piper strut X-rays since the Piper AD came out. (Mid 70's?). They said they have x-rayed 12 T-Crafts here in Alaska so far, and found one strut with some corrosion. The cost was $180.

I understood that X-ray was NOT approved.

Can you post this 9/12/07 letter? or tell us more about it?

Dave.

[AKbrew]

Re: Strut Testing - where, who and what cost? (merged)

I had my struts x-rayed yesterday by Alaska Industrial X-Ray. After evaluating the x-ray they issued me the following log book entry: "X-ray inspection of the Taylorcraft Wing Struts for corrosion in compliance with A.D. 2007-16-14 and approval letter dated 9/12/07 was accomplished. No significant corrosion was found and the following struts are considered airworthy. Corrosion Inhibitor Procedure found in S.B. No. 2007-001 shall be accomplished prior to the return of service." The entry is signed by the inspector, includes the repair station ID and the inspector's certification #. This company has been doing Piper strut X-rays since the Piper AD came out. (Mid 70's?). They said they have x-rayed 12 T-Crafts here in Alaska so far, and found one strut with some corrosion. The cost was $180.

[VictorBravo]

Re: Strut Testing - where, who and what cost? (merged)

CORRECTION our local inspector is a level 2 X-ray NDT and an FAA approved repair station. Apologies for the error.

[VictorBravo]

Re: Strut Testing - where, who and what cost? (merged)

Our local NDT specialist is also a Level 3.

He said clearly that when X-ray'ing a streamlined strut tube, the vertical axis picture is the only one that needs to be done. A picture taken from the front of the streamline tube strut will not work, because there is no part of the "wall" that is nearly perpendicular to the film or the camera.

Also, since the struts are 3 or 4 inches in the fore-aft dimension, shooting through that much metal is difficult and does not show any useful visualization. If it were a round tube or a square tube, then 0 and 90 degree shots are appropriate.

We'll be writing up the procedure and dimensions today and tomorrow, and submitting it to the FAA.

Bill

[dmorlo]

Re: Strut Testing - where, who and what cost? (merged)

Bill, you are correct! Safety is more important than the AD or any service bulletin. X-ray will provide a warm fuzzy on the condition of the strut and the FAA may approve its use as a tool for evaluating struts for this AD. Can you tell me if the x-ray company you used took 2 exposures (1 at a 0 degree mark and 1 90 degrees to it) for 100% coverage? I believe cost wise the ultrasonics can be competitive now that we have reduced the amount of thickness readings to be recorded. Originally I interpreted the service bulletin to require 720 readings using the 1/4" grid but I have since talked to TC Engineer and we only need to scan the 1/4" circumference 48 times over the 12" length for a total of 48 readings. Each circumference will be scanned and the lowest reading recorded.

David Orlosky
Level III, iTi

[VictorBravo]

Re: Strut Testing - where, who and what cost? (merged)

The following is my opinion as a fairly qualified airplane owner but as a non-engineer.

The wall thickness of an undamaged strut is alrerady known. X-ray will be an excellent "screening" method as you say, which will give the owner/mechanic a usable visual indication of the general presence or non-presence of corrosion.

If there is no visible corrosion on the X-ray, then it stands to reason that the wall thickness is still just about where it started, and $500 worth of wall thickness measurements are not necessary.

If an X-ray does show the existence of significant corrosion visually, then the amount of remaining wall thickness is almost a moot point... because it will likely be necessary for the strut to be repaired or replaced. That $500 worth of ultrasound inspection would IMHO be better used towards having the lower 12 inches of the strut replaced, or put toward the purchase of new struts.

You don't throw out an entire airplane because the longerons are rusted... you replace the longerons correctly and fly off into the sunset. Should the struts be any different? Patched struts are common and do not fall apart if done right.

Five of us had X-rays done for $249.00 each. Having seen the inside of my struts visually, I have no qualms about flying the airplane. That is #1 and TEN orders of magnitude more important than an AD, a factory get rich quick scheme, or a federal bureaucracy's ass covering... because the federal rule book says that I am personally responsible for the safety of the aircraft.

[dmorlo]

AD for Taylorcraft Lift Strut Inspection

All owners of TC A, B, and F series planes must comply with FAA Directorate Identifier 2007-CE-057-AD and TC Service Bulletin No. 2007-001.

Some of you may have already received postcards from integrated Technologies, inc. offering our services for nondestructive testing of the lower 12" of the lift struts and if so, you got a big surprise when you called the 1-800 number. No we are not an escort service! Fortunately pilots have a great sense of humor and managed to contact us anyway. We have since sent out new postcards with the correct number 1-800-361-2237.

The TC service bulletin provides the option of eddy current (ET) or ultrasonics (UT) and in my opinion both methods would provide the information needed to evaluate the condition of the struts.

The ET method will not be as accurate in determining the wall thickness. The instrument would be calibrated on known thickness and you would evaluate responses on the scope in the form of a meter reading value or a sinusoidal wave, depending on the instrument used. The actual wall thickness value will be approximate only. If cracking was the major failure mode of the struts, eddy current would be the method of choice as it will find cracks.

The UT method is quick, repeatable and accurate. The remaining wall thickness of the strut can be determined with the accuracy of 0.001". This method has been used for years to find internal corrosion pitting in steam pipes, boiler tubes, condensate piping, tanks, vessels and many more components. About 48 data points will be taken on each strut and stored in the instrument for printout. The report will have the plane serial number and strut identification. A UT data report will be generated for each strut. I am recommending the UT over the ET as it will provide quick and accurate assessment of the struts. This data will be used a baseline so comparisons can be made during the 2 year re-inspection intervals.

Either method chosen requires 360 degree access around the strut for the lower 12" as the probe has to be in contact with the strut. Coatings do not have to be removed but any surface corrosion would have to be cleaned to sound metal. Both methods can be used on all of the models affected by the AD.

The struts can be shipped to one of our offices or we can do the inspection at your home airport or other convenient location. If we inspect in our shop the cost will be fixed at approximately $500.00 per plane. If we travel to the plane travel cost would apply. If multiple plane owners in one location can have struts ready for inspection the travel cost would be split between them.

If struts are shipped to us we anticipate a maximum turnaround of 3 days.

I understand there is going to be a Rev. B to the TC service bulletin allowing the use of x-ray to evaluate the struts. This is fine if your are looking for general wastage and pitting as this would be a great screening tool. The x-ray technique however, will not provide you with an accurate remaining thickness of your strut(s). A density comparison of a known thickness step wedge film to the dark areas of the strut film would be made using a film densitometer, and you will only get an approximate value. You may also not be able to get 100% coverage of the lower 12" due to geometry.

Our company is capable of providing visual, eddy current, ultrasonic, x-ray, magnetic particle and liquid penetrant inspection methods so we are not bias to any one method. We believe you will get the best inspection using ultrasonics.

I hope this helps you with your decision. Please call me at 1-800-361-2237 or 860-447-2474 to discuss further.

David M. Orlosky,

iTi V.P. of NDT Services

[Scott Zimmer]

Re: Strut Testing - where, who and what cost? (merged)

Dear Drude,

Thanks. You are correct.

After reviewing the supplemental information in the Service Bulletin, It is stated that the struts must be removed before performing the Eddy Current or Ultrasonic inspections. Not technically necessary to perform the inspections but a requirement none-the-less.

We can set-up to remove the struts at the airport but bringing or shipping the struts to our facility is much simpler.

We are an FAA Approved Repair Station Certification No. QT9R249N

Our technicians performing the inspections are certified to NAS 410 and SNT-TC-1A American Society of Nondestructive Testing.

All of our technicians either have A&P or Limited rating cards provided by the FAA.

Using qualified people to perform this inspection is critical. Please ask the about the credentials prior to having any NDT performed on your aircraft.

Thank you for your comments. I will list a new Post stating my error.

Scott Zimmer
Quality Testing Services, Inc.
314-770-0607

Re: Strut Testing - where, who and what cost? (merged)

We perform the strut inspection for AD 2007-16-14.

usually 2-3 day turn around if you send the set of struts in to us. The cost is $150. If you want to see X-rays of the area add $75.00 (The X-rays are not required).

If you want us to perform the inspection on the plane, you can fly to Creve Coeur (1H0, one hotel zero) near St. Louis and we will inspect them on the the spot. Cost for this is $150 plus $75 trip charge. You pay only 1 trip charge to the airport, so if you have more planes, the trip charge is divided between each plane.

If you want us to come to your airport, it is still $150 per plane. There is still a trip charge but you will need to call to get a quote. Again, the more planes you have the less expensive it will be.

We take Cash, checks and most credit cards.

Call me personally if you like or our General Manager Steve Stutz to setup an inspection time.

Scott Zimmer

Quality Testing Services, Inc.
2305 Millpark Drive
St. Louis, Missouri 63043
314-770-0607

Read the AD (and the service bulletin it refers to), the AD requires that you remove the struts from the plane.

You really don't have a choice about it.

ADs are law not suggestion, opinion or conjecture. You should and must follow it whether you concur or not.

You put your company, yourself and your customers at risk if you do not.

You will have a hard time defending yourself in court or against the FAA if you use you own method of compliance rather than the one called out in the AD.

Perhaps the statement "...perform the inspection on the plane" is merely meant to mean do the testing in the field versus in the lab if so then I am all wet here. However if not then I suggest you give the AD a very close read before you start.

Does one of you guys have an A&P license to do the signoffs?