What is a pilotless aircraft?

A pilotless aircraft, usually an MAV (micro air vehicle), is one which is programmed to go somewhere or do something on its own, or is a remote controlled aircraft piloted from the ground. Most pilotless aircraft are rather small in size. Pilotless aircraft are used for dangerous jobs such as spying or exploring new places with a camera which transmits the data back to the ground. They can be very useful as many are shot down or crash, and thus saving a real pilot's life.