Airworthiness Directives; Gulfstream Model G-159 Airplanes

This amendment adopts a new airworthiness directive (AD), applicable to all Gulfstream Model G-159 airplanes, that requires repetitive non-destructive testing inspections to detect corrosion of the skin of certain structural assemblies, and corrective action if necessary. This AD also requires x-ray and ultrasonic inspections to detect corrosion and cracking of the splicing of certain structural assemblies, and repair if necessary. The actions specified by this AD are intended to detect and correct corrosion and cracking of the lower wing plank splices and spot-welded skins of certain structural assemblies, which could result in reduced controllability of the airplane. This action is intended to address the identified unsafe condition.