Action
Final rule.
Summary
The FAA is superseding an existing airworthiness directive (AD), which applies to all Model 750 airplanes. That AD currently requires inspecting the inboard-hinge brackets of the left and right elevators for cracking and doing related investigative and corrective actions if necessary. For certain airplanes, this new AD requires inspecting for cracks of the bracket of the inboard horizontal stabilizer and measuring the lug thickness of the horizontal stabilizer hinges; doing corrective actions if necessary; and modifying the left and right elevators and left and right horizontal stabilizer. For all airplanes, this new AD requires replacing the existing elevator assemblies with new elevator assemblies, which terminates the requirements of the existing AD. This new AD also revises the applicability to remove certain airplanes. This AD results from a report of cracking found on the elevator inboard-hinge brackets and the horizontal stabilizer hinges. We are issuing this AD to prevent such cracking of the elevator inboard-hinge brackets and the horizontal stabilizer hinges, which could result in structural failure of the elevators and consequent loss of control of the airplane.