I recently bought the F-27C Stryker and love it! The C version is so much better than the B and flys beautifully. However, I recently suffered a minor crash with it where the prop blades broke clean off the hub. After a little while of figureing out how to get the hub off the shaft to put on a new one, she was ready to fly again. I took it up again this weekend since it's crash but came across a noise issue. All is fine until the engine has to push the plane by it's self at full power, aka, no wind under the wings. When at this point of launching or in a verticle climb at the top of the envelope, the engine puts out a loud high pitched whine. It sounds as if I have taken a big metal stick and hit the inside of a metal pipe. It is that kind of high pitched "ting". It goes away once the engine unloads and and there is air flow over the wings. Can anyone help me decide what this is please? I am afraid the crash damaged a ball bearing or something inside the engine and it will need replacement.
Much appreciated. Thanks!