Summary
We propose to adopt a new airworthiness directive (AD) for certain Gulfstream Aerospace Corporation Models GIII (G-1159A), G-IV, and GIV-X airplanes. This proposed AD was prompted by a report that certain flap tracks were manufactured with the upper flange thickness less than design minimum. This proposed AD would require replacing any defective flap track. We are proposing this AD to address the unsafe condition on these products.