Airworthiness Directives; Boeing Model 747 Series Airplanes

This amendment supersedes 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. The existing AD also provides for optional terminating action for the repetitive inspections. This amendment requires accomplishment of the previously optional terminating action. This amendment 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 this 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.