Airworthiness Directives; Raytheon Model Mitsubishi MU-300 Airplanes

This amendment adopts a new airworthiness directive (AD), applicable to all Raytheon Model Mitsubishi MU-300 airplanes, that requires revising the Airplane Flight Manual (AFM) to provide pilots with certain operating procedures during icing conditions, and to limit the maximum flaps position for flight in icing conditions or landing after an icing encounter. The amendment also requires installing an ice detector, and accomplishing a corresponding AFM revision to address its operation. For certain airplanes, the amendment requires converting the airplane configuration or modifying the warning horn system of the landing gear; and revising the AFM to specify flaps 10 degrees as a normal landing flap configuration. The actions specified by this AD are intended to prevent uncommanded nose-down pitch at certain flap settings during icing conditions.