Airworthiness Directives; Pilatus Aircraft Ltd. Models PC-6, PC-6-H1, PC-6-H2, PC-6/350, PC-6/350-H1, PC-6/350-H2, PC-6/A, PC-6/A-H1, PC-6/A-H2, PC-6/B-H2, PC-6/B1-H2, PC-6/B2-H2, PC-6/B2-H4, PC-6/C-H2, and PC-6/C1-H2 Airplanes

We are adopting a new airworthiness directive (AD) that supersedes AD 2002-21-08, which applies to certain Pilatus Aircraft Ltd (Pilatus) Model PC-6 airplanes. AD 2002-21-08 currently requires you to inspect the aileron assembly for correct configuration and modify as necessary. Since we issued AD 2002-21-08, the FAA determined the action should also apply to all the models of the PC-6 airplanes listed in the type certificate data sheet of Type Certificate (TC) No. 7A15 that were produced in the United States through a licensing agreement between Pilatus and Fairchild Republic Company (also identified as Fairchild Industries, Fairchild Heli Porter, or Fairchild-Hiller Corporation). In addition, the intent of the applicability of AD 2002-21-08 was to apply to all the affected serial numbers of the airplane models listed in TC No. 7A15. This AD retains all the actions of AD 2002-21-08, adds those Fairchild Republic Company airplanes to the applicability of this AD, and lists the individual specific airplane models. We are issuing this AD to correct improper aileron assembly configuration, which could result in failure of the aileron mass balance weight. Such failure could lead to loss of control of the airplane.