The third wheel is either at the nose of the aircraft or the tail. If it is at the nose, it is called a nosewheel, and the aircraft is said to have tricycle landing gear. If it is at the tail, it is called a tailwheel, and the aircraft is said to have conventional landing gear. The main gear also house the braking mechanism for the aircraft. To activate the brakes in most aircraft, you have to push on a pedal above the rudder pedals.
Most aircraft have differential braking.
To activate the left brake only, you apply pressure to the left brake pedal only. In most aircraft, this is how you can steer or enhance steering on the ground. On some aircraft you can simply push on the left or right rudder pedal to move the aircraft either left or right. The Powerplant - The powerplant is simply the system that propels the aircraft. In small aircraft, it consists of an engine and a propeller.