Airworthiness Directives; The Boeing Company Airplanes

We are superseding Airworthiness Directive (AD) 2014-07-01, for certain The Boeing Company Model 747 airplanes. AD 2014-07-01 required repetitive inspections for cracking in certain bulkhead structure; inspections of certain fasteners and support frame modifications on certain airplanes; related investigative and corrective actions, if necessary; and an interim modification that would terminate certain repetitive inspections. This AD clarifies certain paragraph references and revises a compliance time. This AD was prompted by a determination that certain paragraph references are in error. We are issuing this AD to detect and correct fatigue cracking of the BS 2598 bulkhead structure, which could adversely affect the structural integrity of the bulkhead and the horizontal stabilizer support structure, and result in loss of controllability of the airplane.