I flew my 25% H9 CAP 232 w/ OS 1.60FX and 18x6 prop yesterday. Still getting familiar with the plane so I'm not doing much other than simple areobatics, loops, stall turns, split S. About 4 minutes into the third flight I noticed the elevator trim change and the plane started to dive slightly. I gave about 4 clicks of trim to compensate. Elevator response was sluggish, something this plane is not known for, so I knew something was wrong so I made a quick landing. On landing I had barely enough elevator to flare. Upon inspection one elevator half had 2 of the 3 CA hinges fail. They did not pull out they split clean right on the hinge (pivot) line. The balsa structure appears fine and I didn't notice or hear any flutter during the flight. I have a Hitec 5645 metal gear digital servo for each elevator half. The linkage is vitually slop free, straight fiberglass pushrod w/ 4-40 rod. I have only about 15-20 flights on the plane. I have a H9 1.20 UStik with 300+ flights. The CA hinges in my Ustik appear to be the same that came with the CAP. I have abused my USTIK yet all it hinges have survived. I have repaired the elevator half using 5 sig easy hinges. I'm debating if I should cut the hinges on the other elevator half and rehinge that one as well????

Any ideas on the cause???