Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Fokker Model F28 series airplanes. This proposal would require replacement of certain junction fittings of the horizontal stabilizer with improved fittings. For certain airplanes, the proposal also would require replacement of the drive-fitting bushings and bolts of the horizontal stabilizer with improved bushings and bolts. This proposal is prompted by reports of stress corrosion cracking in a junction fitting lug of the horizontal stabilizer. The actions specified by the proposed AD are intended to prevent such cracking, which could result in failure of a lug and uncommanded movement of the horizontal stabilizer. This condition, if not corrected, could result in reduced controllability of the airplane.