Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to all Short Brothers Model SD3-60 SHERPA series airplanes. This proposal would require revising the Airplane Flight Manual (AFM) to provide the flight crew with recognition cues for, and procedures for exiting from, severe icing conditions, and to limit or prohibit the use of various flight control devices. This proposal is prompted by results of a review of the requirements for certification of the airplane in icing conditions, new information on the icing environment, and icing data provided currently to the flight crews. The actions specified by the proposed AD are intended to minimize the potential hazards associated with operating the airplane in severe icing conditions by providing more clearly defined procedures and limitations associated with such conditions.