Airworthiness Directives; Fokker Model F27 Mark 050 Series Airplanes

This amendment adopts a new airworthiness directive (AD) that is applicable to certain Fokker Model F27 Mark 050 series airplanes. This action requires reinforcement of the structural provisions for the Global Positioning System (GPS) antenna by replacement of existing fasteners with new fasteners, and installation of conical washers and a doubler plate at stringer 26, as applicable. This action is necessary to prevent cracking of the structure of the fuselage pressure vessel in the area of the GPS antenna, leading to reduced structural integrity of the fuselage pressure vessel, which could result in depressurization of the airplane. This action is intended to address the identified unsafe condition.