I have a Walkera 450DO and I'm a newbie.
I was messing with heli when I first got it and when I spooled up and it started getting light it started to tilt on its side.
I thought the 3 axis gyro was supposed to correct this, am I wrong?
I realize that on flybar helis you have to counteract this tilt but a 3 axis gyro is supposed to do it for you.
Help!

Did you let the gyro arm and initialize?? If not, when your TX is turned on and of course binded, apply your power to your 450, and set in on a level surface. Don't touch it. Usually if you do not touch your 450 for a while, I wait at least ten seconds, and you should get a solid LED from your mixer, letting you know that it has initiallized, this should correct the problem. Let me know what your results are ! - Drone Ace