Summary
The FAA proposes to supersede an existing airworthiness directive (AD) that applies to certain Boeing Model 767 series airplanes. The existing AD currently requires repetitive detailed and eddy current inspections of the aft pressure bulkhead for damage and cracking, and repair if necessary. This proposed AD would add one-time detailed and high frequency eddy current inspections of any "oil-can" located on the aft pressure bulkhead, and related corrective actions if necessary. An "oil-can" is an area on a pressure dome web that moves when pushed from the forward side. This proposed AD is prompted by reports of cracking at "oil-can" boundaries on the aft pressure bulkhead. We are proposing this AD to detect and correct fatigue cracking of the aft pressure bulkhead, which could result in rapid depressurization of the airplane and possible damage or interference with the airplane control systems that penetrate the bulkhead, and consequent loss of controllability of the airplane.