Who needs the cavalry? US Army calls in the hoverbike - CNET. Forget about Amazon delivery quadcopters. The future for these vehicles is in Army activities. Resupply and logistics are the biggest problem in warfare. Many armies in history have failed because their supply lines are cut, or they outrun them, or weather prevents land based resupply. In the future, development of quadcopters that are remotely controlled would greatly reduce the problems faced by mobile forces. These are the cavalry of the future.