1. Requirement on bit steerability is satisfied with the bit's short gage and active gage protection design.

2. The results indicated that the steerability is more stable and trackable during rear left wheel braking and four-wheel braking.

3. Steerability : The ability to steer a parachute away from an obstacle, or to face oneself into the wind, would be an evident advantage.

4. The mathematics models of shipping control and steering are demonstrated, and the controlling mechanism and steerability of the models are explored.

5. Numerical results show this method is capable of matching the geometrical characteristics of images and has better steerability as well as reconstruction result.