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

This amendment adopts a new airworthiness directive (AD) that applies to all Pilatus Aircraft Ltd. (Pilatus) Models PC-12 and PC-12/ 45 airplanes. This AD requires you to inspect the left and right main landing gear (MLG) assemblies for bolts with a serial number (S/N) beginning with the letters "AT" and numbers 299 or lower and replace each bolt with a bolt that does not have a S/N with both the letters "AT" and a number of 299 or lower. 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 detect and replace defective MLG assembly bolts that have an improper cadmium plating, which could cause hydrogen embrittlement and bolt failure. Such failure could lead to MLG collapse during landing.