Another form of control, which is less common now than it once was, is to steer using "differential braking", in which the tailwheel is a simple, freely castering mechanism, and the aircraft is steered by applying brakes to one of the mainwheels in order to turn in that direction. This is also used on some tricycle gear aircraft, with the nosewheel being the freely castering wheel instead. Like the steerable tailwheel/skid, it is usually integrated with the rudder pedals on the craft to allow an easy transition between wheeled and aerodynamic control.