Early aircraft AUTOBRAKE systems controlled airplane deceleration to one of several predetermined aircraft deceleration settings. Thus, if a pilot wished to stop the airplane at a certain point on the runway, for example at a runway exit, it is unlikely that the AUTOBRAKE system would provide a deceleration setting that matched the stopping distance to the selected runway stop point. The pilot's choice, then, was to select one of the deceleration settings, and, if the airplane was decelerating too quickly, the pilot can select another AUTOBRAKE setting or disarm the AUTOBRAKE system and use pedal braking to avoid stopping short of the desired point. If, however, the airplane was decelerating too slowly, the pilot would again need to revert to a different AUTOBRAKE setting or to pedal braking to increase deceleration to stop the airplane at the selected stopping point. Both of the above conditions resulted in uneven deceleration that is apparent to the airplane passengers.
Aircraft AUTOBRAKING systems have been developed which apply predetermined braking to an aircraft. These AUTOBRAKING systems typically provide four or five selectable deceleration rates which can be used to decelerate the landing aircraft at the deceleration rate selected by the pilot. The result being either the braking of the aircraft at a specific rate until stopped or the pilot taking command of braking before the aircraft stops.
Modern aircraft can have the ability to determine position on the runway, calculate the deceleration rate for a specific exit taxiway on that runway, and automatically modulate the application of the brakes so as to arrive at the exit taxiway at a speed slow enough as to exit at the predefined exit taxiway.