Airworthiness Directives; Pilatus Aircraft Ltd. Model PC-12 Airplanes

This action confirms the effective date of Airworthiness Directive (AD) 98-05-06, which applies to Pilatus Aircraft Ltd. (Pilatus) Model PC-12 airplanes. AD 98-05-06 requires inspecting the elevator for incorrect rivet lengths and installing new rivets if incorrect rivet lengths are found. This AD also requires inspecting the elevator to assure that an excessive gap (more than .004 inches or .1 millimeters (mm)) does not exist in the rivet shanks, and installing a shim between the rib and skin to fill any excessive gap. This AD is the result of mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for Switzerland. The actions specified in this AD are intended to prevent fatigue damage to the elevator, which could result in structural failure and eventual loss of control of the airplane.