Lift Strut Inspection

[Steve Pierce]

$2270 new from Univair. I wonder why they are any more than Pacer or Clipper struts? You just have to do the inspection of the struts and forks per the AD.

[taildragger]

$2270 new from Univair. I wonder why they are any more than Pacer or Clipper struts? You just have to do the inspection of the struts and forks per the AD.

So I can use the unsealed struts then. I take it I just need to have them inspected annually

[Glen Geller]

Inspect everything before installation. If they pass, install them per the CD so wings are in rig, your AP will help you rig it. The inspection per AD must be repeated after 24 calendar months.

[tnowak]

Taildragger,

It may be worth getting your friend's struts (that you are going to buy), X-rayed first to see if anything really nasty shows up. Then you have a baseline to work from regarding your 24 monthly ultrasound inspections.
I was lucky in that I had access to an airline maint. facility NDT shop and qualified NDT engineer who did my inspections and provided the paperwork at very reasonable cost. Did this for 12 years and then the NDT shop replaced their NDT equipment last year which wasn't suitable for the strut inspection task. Going to another NDT facility and paying "normal commercial rates" would make these 24 month inspection quite expensive. Not sure what they cost in USA but may be worth enquiring.
That is why I decided it was time to buy new struts and fork ends from Univair.
TonyN

[taildragger]

Thanks Tony. I learn so much when I come to the site and really appreciate the information from everyone. The costs are just starting to kill me as in my case there is only so much money to work with, but I guess I will have to make the wife mad again and tell her I need more money for the project. Thank you for the comeback.

[Lownslow]

I see no mention that the alternate method listed in the AD using SB 528D (use of Maule Fabric Tester). It is my interpretation of the AD that either method is specified by the AD for continued use of the old struts per par (a) (3) of AD 99-01-05. Someone enlighten me if I am not interpreting this right.

Lou

[Lownslow]

Thought I might get a comment here.

Lou

[Glen Geller]

You are correct Sir! I do the delightful Maule punch test every two years on my original PA22 struts.
Go to the stationary or school supply store and buy some LEGAL SIZE graph paper with 1/4" grid (or closer) and some masking tape.
Drain the fuel tanks most of the way to reduce the weight.
You have to remove the struts one at a time or build a brace to support the wings if you pull them both.
Lay out sawhorses or a long table with some padding, lay the strut down and wrap the lower 13.5" (starting at the weld of the nut) taping at top and bottom.
DO NOT remove the fork, unless it's due for 500 hr inspection. Then measure the total length and label every part so they will go back they way they were. This is vital to keep your plane in correct rig!
Now punch the graph paper to 80# (?) on every gid intersection, top to bottom, all the way around. Use care not to slip and tear the paper, just tape it or replace it.
If you dent or penetrate the struts at all, game over baby, break out the checkbook!
After a few years I made a hardwood handle to protect my hands from the Maul tester.
Once you have tested a strut and it has passed, you need to pour a quart of linseed oil (or possibly Corrosion X is approved?) and slosh it around all over the inside of the strut. And then stand it up on the fork end so the oil soaks into the bottom section of the strut. Tie it to the wall or whatever to avoid it falling over.
Hints: Work away from your plane so you don't clonk it with the strut while sloshing the strut around.
And the linseed oil can make a mess so have a clean bucket to put the strut into to drain it after the interior has been thoroughly coated.
Using a syringe or small funnel and tubing to get it in the strut thru the upper bolt hole takes a bit of figgering out. You can cap the holes at the upper bolt and strut cuff screw hole with duct tape (tho that may damage the paint a bit.)
After nearly ten years of this I can get a strut off, punched, lubed and back on in about 90 minutes.

Have fun, it's really not very hard and once you have done one, the other three are cake.
Glen the Technical Writer

[Lownslow]

That is exactly how I have done it, Glen. Thanks for following up. It's just that it almost takes a Philadelphia lawyer to fully grasp the contents of this particular AD note, as it is not really "crystal clear" as is in most AD notes that there is an Option A,B, or C. I believe that after reading this AD multiple times the writer missed the opportunity to have the intent completely conveyed in a manner that us earthlings would have no question to. I also believe that the linseed oil application is intended to be done only once, and that the inspection, whether by use of Maule fabric tester or ultrasonic testing, be done on a two-year frequency. This also is not as "clear as mud" as one would expect. Of course, installation of the sealed struts and forks stops all of the inspection requirements.

Lou

[Glen Geller]

Several A&P an IA we have worked with,and our own educated interpretation of the AD concur, you must do the linseed oil at every interval.
Regardless, it's cheap insurance, especially if you live anywhere that sees weather.