Airworthiness Directives; Fokker Model F28 Mark 1000, 2000, 3000, and 4000 Series Airplanes, and Model F28 Mark 0100 Series Airplanes

This amendment adopts a new airworthiness directive (AD), applicable to certain Fokker Model F28 Mark 1000, 2000, 3000, and 4000 series airplanes, and Model F28 Mark 0100 series airplanes, that requires repetitive pre-load adjustments of the main landing gear (MLG) downlock-actuator. This AD also provides optional terminating action for the repetitive adjustments. This amendment is prompted by a report that, upon landing, the MLG of an airplane collapsed as a result of the lock toggle-links being pulled out of the over-center position by the downlock-actuator, which was due to the relative movement of the upper and lower side-stay members. The actions specified by this AD are intended to prevent collapse of the MLG, which could adversely affect the controllability of the airplane during landing.