AD 99-04-21 Amendment 39-11046

This amendment adopts a new airworthiness directive (AD) that applies all British Aerospace Jetstream Model 3101 airplanes that have a certain wheel assembly incorporated and all Jetstream Model 3201 airplanes that are equipped with Dunlop AH54450 brake units. This AD requires inspecting the main landing gear brake units for correct setting of the wear indicator pins, and re-setting the pins if incorrect. This AD is the result of mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for the United Kingdom. The actions specified by this AD are intended to prevent failure of the main landing gear brakes because the wear indicator pins present a false indication of the remaining wear of the brake units, which could result in loss of control of the airplane during takeoff, landing, or taxi operations.