blade 450

My blade 450 was flying fine then the tail decided not to cooperate, the tail drifts pretty severely. Gain adjustments didn't work, belt tension is good. I replaced the gyro only to have the same problem, and I even tested it with a new servo but it does the same thing. I reset the model and...

I have my helicopter trimmed right side up, but when I flip it inverted in a hover it wants to go backwards. Any ideas on why it is doing that? Thanks