AD/CFM56/28 - Low Pressure Turbine Rear Frame (Cth)

AIRWORTHINESS DIRECTIVE For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.001(1) of CASR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.

CFM International Turbine Engines - CFM56 Series AD/CFM56/28 Low Pressure Turbine Rear Frame 3/2009 DM

Applicability: CFM International CFM56-7B turbofan engines equipped with a low pressure turbine (LPT) rear frame part number (P/N) 340-166-254-0, 340-166-255-0, 340-166-256-0, 340-166-257-0, 340-166-258-0, 340-166-259-0, 340-177-551-0, 340-177-552-0, 340-177-553-0, 340-177-554-0, 340-177-555-0, 340-177-556-0.

Note 1: These engines are known to be installed on, but not limited to, Boeing 737series aeroplanes. Requirement: 1. Amend the approved operator maintenance programme to incorporate the new LCF life limits for LPT rear frame P/N 340-166-254-0, 340-166-255-0, 340-166-256-0, 340-166-257-0, 340-166-258-0, 340-166-259-0, 340-177-551-0, 340-177-552-0, 340-177-553-0, 340-177-554-0, 340-177-555-0, 340-177-556-0, in accordance with the CFM56-7B ESM chapter 05 Temporary Revision (TR) 05-0097, 05-0098, and 05-0099, as applicable or subsequent revisions of the Engine Shop Manual following Revision 38 that incorporate these Temporary Revisions.

2. If the number of total cycles accumulated by a LPT rear frame P/N 340-166-254-0, 340-166-255-0, 340-166-256-0, 340-166-257-0, 340-166-258-0, 340-166-259-0, 340-177-551-0, 340-177-552-0, 340-177-553-0, 340-177-554-0, 340-177-555-0, 340-177-556-0 cannot be positively established, remove and replace the LPT rear frame or perform the inspections in accordance with CFM56-7B Service Bulletin S/B 72-0558 revision 2, or CFM56-7B Service Bulletin S/B 72-0579 revision 4, as applicable.