Need tube frame info/specs for Kitfox III repair

[ravn]

Hi, I have to do some tube frame repair/fabrication on my Kitfox III. The damage is on the left side under the left seat. Kit fox would not let out the information. Does anyone have some resources? I also need the bottom part of the round cowling or both if necessary.

[szicree]

I don't know the answer to your question, but I am troubled by the manufacturer not releasing the info. Are we simply talking about alloy, diameter and wall thickness? Shouldn't a builder/pilot/owner know what his plane is made of?

[jtpitkin06]

Using good repair practices shouldn't be a problem. Simply cut and grind out the damaged piece, measure the wall thickness and diameter, then weld in a new tube. The FAA Airframe Mechanics Handbook shows examples of tube airframe repairs and techniques.

4130 steel is adequate as there is nothing in the airframe made of exotic metals.

John Pitkin
Greenville, TX

[DesertFox4]

I am troubled by the manufacturer not releasing the info. Are we simply talking about alloy, diameter and wall thickness? Shouldn't a builder/pilot/owner know what his plane is made of?

As John indicated it is easy to find the tube wall thickness of the early Kitfox's during a repair.


Remember guys that Kitfox Aircraft LLC is not the manufacturer of the early 1's 2's 3's 4's 5's 6's and 7's. Maybe there's liability factors involved for giving info. out about someone else's design. In this day and age that would be my best guess but I was wrong one other time.
Good luck on the repairs ravn. Hope you're back in the air soon.

[jdmcbean]

Hi, I have to do some tube frame repair/fabrication on my Kitfox III. The damage is on the left side under the left seat. Kit fox would not let out the information. Does anyone have some resources? I also need the bottom part of the round cowling or both if necessary.

We do not release engineering drawings.. the tubing is most likely 4130 and it is best to measure the tubing you actually have. The earlier models may have had a repair done and a different tubing size was used... even at that changes were happening rapidly at Denny Aerocraft and while many of the OD's were the same.. some of the wall thicknesses would change.

[szicree]

Remember guys that Kitfox Aircraft LLC is not the manufacturer of the early 1's 2's 3's 4's 5's 6's and 7's. Maybe there's liability factors involved for giving info. out about someone else's design.

Good point. I really hadn't thought about the liability issue. In any case, it sounds like standard repair practices will get the job done.