Airworthiness Directives; SIAI Marchetti S.r.1. Models SF600 and SF600A Airplanes

Résumé

This document proposes to adopt a new airworthiness directive (AD) that would apply to all SIAI Marchetti S.r.1. Models SF600 and SF600A airplanes. The proposed AD would require amending the Limitations Section of the airplane flight manual (AFM) to prohibit the positioning of the power levers below the flight idle stop while the airplane is in flight. This amendment would include a statement of consequences if the limitation is not followed. The proposed AD is a result of numerous incidents and five documented accidents involving airplanes equipped with turboprop engines where the propeller beta was improperly utilized during flight. The actions specified by the proposed AD are intended to prevent loss of airplane control or engine overspeed with consequent loss of engine power caused by the power levers being positioned below the flight idle stop while the airplane is in flight.