Jury Strut Clamp Cracking

[BigJohn]

Time for my first Annual Inspection on a Series 5 that I purchased already built last year, and I found that both the front Jury Strut Clamps were cracked between 1/2 & 3/4 the way through, They were not visiable until I removed the Strut Fairings. The plane was completed in 2002 so I have no idea how complete the past Inspections were.

I believe that one of the probable or possible reasons is that these clamps had been powder coated which may have caused them to become more brittle.

I checked with Kitfox and they do not powder coat the clamps so it most likely was done at some other point, Deb is sending me 4 new one's. Just thought I would bring this to everyone's attention so that we could all be more aware.

[t j]

John, where on the clamps were the cracks? My strut fairing is bonded with structrual adhesive. I don't think I could remove it without destroying it.

[BigJohn]

Both of the Front Clamps were cracked in the front right where the bend occures from straight to rounding to fit around the Strut. As I mentioned, Kitfox say's they have not seen any failures like this but they also indicated to me that they don't powder coat them which had been done on mine, Most likely hardening the alum and making it more brittle.

Not sure how you would check yours if they are completly covered? I just thought I had better mention this so other's could check and make sure they didn't have any issues. I didn't mention that I have just over 700hrs on the plane.

[HighWing]

Interesting observation and comment regarding powder coating. I have heat treated aluminum for some projects and some temps are well within the reach of most kitchen ovens - not glowing temps like steel. I personally would suggest avoiding powder coating on any aluminum structural components - this includes landing gear.
Lowell

[t j]

I was suspecting that's where. I may be able to see that spot on mine. I installed the fairing after I had been flying for about a 100 hours and no sign of cracks then. I agree the powder coating process might have weakened them. I don't think there is much strain on the clamps.