Last Saturday, I burned off all my luck for the next season.

I am new to gas, larger models, and 3D. I traded another airplane for this Chip Hyde CAP 232, partially built by a person I don't know. He had already installed the elevators, with the kit supplied CA hinges (about 1 inch wide at the hinge point). I completed the model in the middle of the summer, and have about fifteen flights on it. It has a FPE 2.4 (40cc) engine, swinging a 20x10 APC ... at full throttle I get 7200 RPM, which the manual for the engine says is normal.
I am wary of flying too fast, because of flutter, and I do use a lot of throttle management. Normal cruise is at around 25 to 30% throttle. 625MG's on elevator, 645MG's on everything else. She weighs around 12 pounds, and the engine pulls around 20.

On the last flight of Saturday (about 45 degrees F, zero wind), I did some stall turns, an upright flat spin, and a harrier (high up there). A few Split -S's, loops (full throttle up side, idle down side), etc etc. I noticed that I was trimming the elevator during the flight, but I cannot remember if it was for the whole flight or not. I had a little trouble getting down -- this ship makes a hamfisted pilot like myself look great on landings, but this time, I was chasing pitch all through the descent. It took three approaches to get her on the ground, and one "touch and go" was in there that was more like an F-16 carrier landing. The last landing was perfect.

I flipped her over to look the LG over from the hard T&G, and noticed that the gap sealing film on the right elevator half was torn up. Inspecting the elevator for the cause revealed that the inboard and outboard CA hinges on that half were completely severed, and only the center hinge was intact. The other side elevator was fine.

I have removed the CA hinges from both elevators, and am replacing them with pinned giant scale hinges. However, I would like to understand the cause of the failure of the CA hinges. The options I can think of are:
1) Somehow the installer cut the hinges during installation
2) The hinges fatigue failed, because they are no good
3) I flew too fast, or had too much power on, and fluttered the surface

I am going with 3), but I have to say that I do not know WHEN I flew too fast. Is it wrong to flat spin at full throttle? I did that. Going vertical and the upside of loops are the only other times I use full throttle. Any other thoughts? Right now I am looking forward to flying her in fear that I am always going too fast, because I apparently do not know the limits. Thanks in advance for any help here, guys.
Regards to all,
Rikk

i have ca hinge falure on 90 size planes on the time. i do throw alot at my planes but nver lost one due to it. but i always check my alerons. they just snap after a while the ca make them a little brittle then all the back and foward bending can snap them or just pull them out of the plane.
the giant scale pin hinges will work well.
good luck!

I suppose all CA hinges can fail eventually, but I've had very good luck and highly recommend Radio South Pro CA hinges for larger planes. Have never had one of them fail and had them in service on some planes for years.