Airworthiness Directives; Aerospatiale Model ATR-42 and ATR-72 Series Airplanes

This amendment adopts a new airworthiness directive (AD) that is applicable to all Aerospatiale Model ATR-42 and ATR-72 series airplanes. This action requires revising the Airplane Flight Manual (AFM) to add specific flightcrew instructions to be followed in the event of failure of one or both of the direct current (DC) generators. This amendment is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified in this AD are intended to prevent failure of the second of two DC generators after the failure of the first generator, which could lead to the loss of main battery power and result in the loss of all electrical power, except the emergency battery supply, during flight.