Airworthiness Directive · Amendment 39-12318 · Boeing Model 747 Series Airplanes
Boeing Model 747 Series Airplanes
Superseded. A later AD replaced this one: AD 2006-05-06. Comply with the one in force.
Model 747 series airplanes, as listed in Boeing Service Bulletin 747-53A2449, Revision 1, dated May 24, 2001, certificated in any category.
This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing Model 747 series airplanes, that requires repetitive high frequency eddy current inspections to find cracking of the bulkhead frame support at body station 2598 under the hinge support fittings of the horizontal stabilizer, and repair if cracking is found. These actions are necessary to find and fix fatigue cracking in the frame support, which could result in inability of the structure to carry horizontal stabilizer flight loads and reduced controllability of the horizontal stabilizer. This action is intended to address the identified unsafe condition.
