AD 90-20-13

90-20-13 CFM INTERNATIONAL: Amendment 39-6679. Docket No. 90-ANE-16. Applicability: CFM56-3B-2 and CFM56-3C-1 series turbofan engines equipped with fan blade Part Numbers (P/N's) 9527N99P08, 9527M99P09, 9527M99P10, 9527M99P11, and 1285M39P01. The above noted engine models are installed in, but not limited to, the Boeing 737-300/400/500 series aircraft. Compliance: Required as indicated, unless previously accomplished. To prevent fan blade failure, inflight shutdown, and severe engine damage, accomplish the following: (a) Modify the fan module assembly by installing fan blade dampers P/N 335-105-305-0, axial stops P/N 335-105-201-0, and bolts P/N J815PO56A, in accordance with the accomplishment instructions contained in CFM56 Service Bulletin 72-494, Revision 2, dated June 18, 1990, within 60 days from the effective date of this AD. (b) Aircraft may be ferried in accordance with the provisions of FAR 21.197 and 21.199 to a base where the AD can be accomplished. (c) Upon submission of substantiating data by an owner or operator through an FAA Airworthiness Inspector, and alternate method of compliance with the requirements of this AD or adjustments to the compliance schedule specified in this AD may be approved by the Manager, Engine Certification Office, Engine and Propeller Directorate, Aircraft Certification Service, Federal Aviation Administration, 12 New England Executive Park, Burlington, Massachusetts 01803. The installation of fan blade friction dampers and associated hardware into the fan module assembly shall be done in accordance with the following CFMI document:

DOCUMENT PAGE REVISION DATE CFMI SB 72-494 ALL 2 June 18, 1990

This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552 (a) and 1 CFR Part 51. Copies may be obtained from CFM International, Technical Publications Department, 1 Neumann Way, Cincinnati, Ohio 45215. Copies may be inspected at the Regional Rules Docket, Office of the Assistant Chief Council, New England Region, 12 New England Executive Park, Room 311, Burlington, Massachusetts 01803, or at the office of the Federal Register, 1100 L Street, NW, Room 8301, Washington, D.C. 20591. Amendment (39-6679, AD 90-20-13) became effective on October 14, 1990.