Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Boeing Model 747 series airplanes. This proposal would require repetitive inspections to detect evidence of wear damage in the area at the interface between the vertical stabilizer and fuselage skin, and corrective actions, if necessary. This proposal also would provide for an optional terminating action for the repetitive inspections. This action is necessary to detect and correct wear damage of the fuselage skin, which could result in thinning and cracking of the fuselage skin, and consequent in-flight depressurization of the airplane. This action is intended to address the identified unsafe condition.