Airworthiness Directives; British Aerospace Model BAe 146 and Avro 146-RJ Series Airplanes

This amendment adopts a new airworthiness directive (AD), applicable to all British Aerospace Model BAe 146 and Avro 146-RJ series airplanes, that requires modification of the left and right elevators, and replacement of the elevator spring with a stiffer spring. This amendment is prompted by reports indicating that water and ice have accumulated at the trailing edge of the left and right elevators; this accumulation can cause the elevators to become unbalanced, and oscillate or flutter. The actions specified by this AD are intended to prevent this oscillation or flutter. Elevator oscillation, if not corrected, could result in reduced controllability of the airplane. Elevator flutter, if not corrected, could couple with the natural vibrations of the airplane, and result in loss of the airplane's structural integrity.