WWIIbirds

I'm participating in a competition that requires my team and I to build an Autonomous Hovercraft (no RC input). The rules are that the hovercraft must travel 30m in a straight line as fast as possible. Because we have no RC input we're thinking that a gyro would be a good solution, I went to my LHS today and asked if it were possible to do and they told me that all the gyros they carry required 2 inputs a gain and one from the transmitter. This doesn't work for us because one, we're on a budget and two like i previously mentioned it has to be autonomous.

Essentially we want to connect the gyro to a servo which would move the propulsion fan blade of hovercraft to correct for any deviation in yaw.

What I'm wondering is; are there gyros that don't require the RC input or, and I asked the guy at my LHS if the gyro had a default input when nothing was plugged in and would work anyway but he wasn't sure.

Any help at all would be much appreciated. Or any alternative suggestions would be great, thanks so much!