Collision not working

Hi I tried so many thing to stop my Helicopter to stop going through floor but i am not understanding what is causing issue Can anyone help me fixing this.

Here is my project : link text

controls -
W+Shift = liftup
W+LeftCtrl = Down

Hi, I didn’t look at the project, but AFAIK with any build in movement component it only uses the root component for movement collision. So if your helicopter is not the root, then it will be ignored for movement.

But if i change the root component helicopter is not lifting up in air