GULFSTREAM AEROSPACE CORP. AIRPLANES [Docket No. FAA-2017-0910; Product Identifier 2017-CE-027-AD; Amendment 39-19136; AD 2017-26-05] The FAA is adopting a new airworthiness directive (AD) for certain Gulfstream Aerospace Corporation Models G-1159A (GIII), G-IV, and GIV-X airplanes. This AD was prompted by a report that certain flap tracks were manufactured with the upper flange thickness less than design minimum. This AD requires replacing any defective flap track. The FAA is issuing this ...