Summary
The FAA proposes to adopt a new airworthiness directive (AD) for all Pilatus Aircraft Ltd. (Pilatus) Models PC-12 and PC-12/45 airplanes. This proposed AD would require you to check the airplane logbook to determine whether certain inboard and outboard flap flexshafts have been replaced with parts of improved design. If the parts of improved design are not installed, you would be required to replace certain inboard and/or outboard flap flexshafts with the parts of improved design. The pilot is allowed to do the logbook check. If the pilot can positively determine that the parts of improved design are installed, no further action is required. This proposed AD is the result of mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for Switzerland. We are issuing this proposed AD to prevent rupture of the flap flexshafts due to corrosion, which could result in failure of the flap system. This failure could lead to loss of control of the airplane.