I bought a 9006 3-Channel Black Air Shark KA-50 RC Helicopter with Gyro from xheli. At first, it worked very well and had no issues flying; however, after a light crash (from about 3 ft up and in the grass, mind you) it won't even take off. It now just spins in circles on the ground. I did notice that the lower rotor was spinning significantly more slowly than the upper.
What is causing this? Is it fixable?

Here is the link to helicopter:
http://www.xheli.com/28h-9006-apacheheli-black.html