You probably already know this but check your proportional pot on your 3 in 1...Decreasing it will make the nose spin to the left more...Hopefully your tail motor isn't going on ya. 20 hours is approximately the life of the tail motor...Check your TX trims and make sure you didn't bump them over. You'd be amazed on the few that didn't realize this before, so I have to say it...Lol.. It's stuff you probably already know, but I had to remind ya any way.. Good luck, let's us know what ya find for a solution... Jeff