Hello Lowell,

I did a wheel landing at Dug bar, with no unusual bumps. I'm not sure exactly when the bolt snapped, but I'm thinking it snapped when I was taxiing over to park at Dug Bar. The ground at Dug bar was dried out and there were dried ruts in the runway and taxi area. After inspecting the bolts when I disassembled the spring I noticed the grip on the AN3-12a was not long enough to clear the top mounting plate. Right at the shoulder of the grip was shinny due to a small amount of rubbing. Just into the thread of the bolt is where the bolt sheered off. With only 25 in-lb torque on the bolts there is not enough compression to squeeze the 3 springs together completely. That spring play is where you get the movement right at the shoulder of the grip on the AN-3-12A. At a minimum to fix the issue you need a bolt with a longer grip AN3-13A. A better fix in my opinion is to replace the bolt with an AN4 along with a block between the plates to distribute the load between the plates. The new design from Kitfox does exactly that. The bottom and top bracket that holds the spring is completely mated and held together with AN4 bolts. I have it installed now and used it for about 8 landings. The grove spring and mounting setup is much stronger. I am much more confident the new spring setup I have will last although I am going to carry and extra set of bolts in the back country. Since this experience I've foand that it is common for pilots to carry extra tail wheel bolts when landing ln the Back Country. Several people that I have talked to even change the tail wheel bolts out every annual.