Airworthiness Directives; Jetstream Aircraft Limited HP137 Mk1 and Series 200 Airplanes

Résumé

This document proposes to adopt a new airworthiness directive (AD) that would apply to Jetstream Aircraft Limited (JAL) HP137 Mk1 and series 200 airplanes. The proposed action would require incorporating operating limitations that revise the maximum flap operating speed for DOWN flaps to 120 KIAS, and that prohibit extending the flaps beyond the take-off position if ice is visible on the airplane. An incident where an airplane of similar type design to that of the affected airplanes experienced sudden pitch down because of the accretion of over one-inch of ice prompted the proposed action. The actions specified in this proposed AD are intended to prevent sudden pitch down of the airplane during icing conditions, which could lead to loss of control of the airplane.