Summary
This document proposes the supersedure of an existing airworthiness directive (AD), applicable to certain Boeing Model 747 series airplanes, that currently requires repetitive high frequency eddy current (HFEC) inspections to detect cracking on all surfaces of the upper recesses in certain latch support fittings of the cargo doorway, and replacement of cracked fittings with new fittings. That AD also provides for optional terminating action for the repetitive inspections. This proposal would require accomplishment of the previously optional terminating action. This proposal is prompted by reports indicating that the repetitive inspections required by the existing AD may not detect cracked fittings in a timely manner. The actions specified by the proposed AD are intended to prevent the cargo door from opening while the airplane is in flight, which could result in rapid decompression of the airplane.