Summary
This document proposes to adopt a new airworthiness directive (AD) that would apply to certain Twin Commander Aircraft Corporation (Twin Commander) 685, 690, and 695 series airplanes. The proposed action would require initially inspecting the vertical stabilizer for cracks, modifying any cracked vertical stabilizer, and, if not cracked, either repetitively inspecting or modifying the vertical stabilizer. Several reports of the vertical stabilizer cracking in different areas prompted the proposed action. The actions specified by the proposed AD are intended to prevent failure of the vertical stabilizer as a result of cracking, which, if not detected and corrected, could result in loss of control of the airplane.