COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Boeing 727 Series Aeroplanes AD/B727/61 Amdt 2 Rear Pressure Bulkhead Vertical Beams 6/86 Applicability: Models 727-100, -100C and -200 aircraft with fuselage numbers 1 to 743. Requirement: Inspect in accordance with Boeing Alert Service Bulletin No. 727-53A0173 Revision 1. Note: FAA AD 85-20-03 refers. Compliance: As detailed in the Requirement Document. Note: Installation of reinforcing angle doublers on the vertical beam lower ends in accordance with the Requirement Document or SB 727-53-55 (Revision 3 or later issues) constitutes terminating action for the inspections. Aircraft modified in accordance with SB 727-53-55 Revision 2 or earlier issues require an additional one- time inspection. Background: An FAA AD has been issued because of recent reports of multiple vertical beam cracks. In one case the web was also cracked. Undetected cracks could lead to rapid decompression in flight. No Australian registered aircraft are affected at the time of issue of this Directive amendment. This amendment has become necessary because the manufacturer has re-arranged some of its SBs. SB 727-53A0173 now contains all the information relating to the vertical beams. Background: An FAA AD has been issued because of recent reports of a multiple vertical beam cracks. In one case the web was also cracked. Undetected cracks could lead to rapid decompression in flight. No Australian registered aircraft are affected at the time of issue of this Directive amendment. This amendment has become necessary because the manufacturer has re-arranged some of its SBs. SB 727-53A0173 now contains all the information relating to the vertical beams.