Summary
This document proposes the supersedure of an existing airworthiness directive (AD), applicable to certain Boeing Model 747 series airplanes, that currently requires a one-time inspection to identify all alloy steel bolts on the body station 1480 bulkhead splice, and corrective action if necessary; and provides for optional terminating action for certain requirements of that AD. This proposed AD would require accomplishment of the previously optional terminating action. The actions specified by this proposed AD are intended to prevent cracked or broken bolts, which could result in structural damage and rapid depressurization of the airplane. This action is intended to address the identified unsafe condition.