Airworthiness Directives; Pilatus Aircraft Ltd. Models PC-12 and PC-12/45 Airplanes

This amendment adopts a new airworthiness directive (AD) that applies to certain Pilatus Aircraft Ltd. (Pilatus) Models PC-12 and PC- 12/45 airplanes. This AD requires modifying the flap inboard attachment fittings through the installation of a reinforcement angle bracket on the inside of the center web of both flap inner attachment fittings. This AD is the result of mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for Switzerland. The actions specified by this AD are intended to prevent the potential of the inboard flap attachment fittings buckling while operating at full flaps with full power into a head-on wind gust, which could result in loss of control of the airplane.