Aviation Technical Services, Inc.

The AD refers to Boeing Alert Service Bulletin 757-27A0153, dated May 9, 2012, and corrections provided by a later revision of the same Boeing Alert Service Bulletin (Revision 1, dated October 29, 2012). This will require operators and maintenance providers to integrate the two bulletins in order to comply with the AD. This burden should be on the OEM and the FAA. To reduce compliance risk and to simplify the instruction, I highly recommend that the FAA requires Boeing to incorporate the two Alert Service Bulletins into one final revision. Refer to the final revision as a basis for complying with the AD. The instructions provided by Alert Service Bulletin 757-27A0153, dated May 9, 2012 refers to Boeing SOPM 20-50-03 as the shrink fit procedure for installing repair bushings. The referred-to SOPM procedure contains instructions such as “Apply the specified installation finish…” and “Refer to the overhaul instructions for applicable operations….”. Neither the Service Bulletin nor SOPM provide sufficient instruction to determine the installation finish associated with the replacement bushing for the rudder pedal pushrod. To further determine the adequacy of the Boeing Service Bulletin, the FAA should use its own guidance as provided by FAA Advisory Circular 20-176 “Design Approval Hlder Best Practices for Service Bulletins Related to Airworthiness Directives”.