93-14-13 TEXTRON LYCOMING: Amendment 39-8637. Docket 91-ANE-55.
Applicability: Textron Lycoming ALF502R and ALF502L turbofan engines installed on but not limited to British Aerospace BAe-146 and Canadair Challenger CL600 aircraft.
Compliance: Required as indicated, unless accomplished previously.
To prevent third stage turbine disk failure, which could result in engine shutdown, accomplish the following:
(a) For ALF502R series engines with installed third stage turbine rotor shaft assemblies, Part Number (P/N) 2-143-040-12, P/N 2-143-040-15, or P/N 2-143-040-16, rework the third stage turbine disk blade slots and mark the third stage turbine assembly with a new part number in accordance with the Accomplishment Instructions of Textron Lycoming Service Bulletin (SB) No. ALF502R 72-270, dated March 31, 1992, or replace with a serviceable part as follows:
(1) For third stage turbine disks with 15,000 or more cycles in service (CIS) on the effective date of this AD, within 1,000 CIS after the effective date of this AD.
(2) For third stage turbine disks with 10,000 or more CIS but less than 15,000 CIS on the effective date of this AD, within 1,000 CIS, after the effective date of this AD, or at the next shop visit, whichever occurs later, but prior to accumulating 16,000 CIS since new.
(3) For third stage turbine disks with less than 10,000 CIS on the effective date of this AD, at the next blade removal, but prior to accumulating 13,000 CIS since new.
(4) For third stage turbine disks not reworked in accordance with the requirements of this AD and installed on Textron ALF-502R engines as replacement disks when complying with this paragraph, accomplish the requirements of this paragraph as to that replacement disk.
(b) For ALF502L series engines with installed third stage turbine rotor shaft assemblies, Part Number (P/N) 2-143-040-10, P/N 2-143-040-11, P/N 2-143-040-12, P/N 2-143-040-15, or P/N 2-143-040-16, rework the third stage turbine disk blade slots and mark the third stage turbine assembly with a new part number in accordance with the Accomplishment Instructions of Textron Lycoming SB ALF502L 72-270, dated April 30, 1993, or replace with a serviceable part as follows:
(1) For third stage turbine disks with 15,000 or more CIS on the effective date of this AD, within 1,000 CIS after the effective date of this AD.
(2) For third stage turbine disks with 10,000 or more CIS but less than 15,000 CIS on the effective date of this AD, within 1,000 CIS after the effective date of this AD or at the next shop visit, whichever occurs later, but prior to accumulating 16,000 CIS since new.
(3) For third stage turbine disks with less than 10,000 CIS on the effective date of this AD, at the next blade removal, but prior to accumulating 13,000 CIS since new.
(4) For third stage turbine disks not reworked in accordance with the requirements of this AD and installed on Textron Lycoming ALF-502L engines as replacement disks when complying with this paragraph, accomplish the requirements of this paragraph as to that replacement disk.
(c) For the purpose of this AD, a shop visit is defined as the induction of an engine into a shop for maintenance.
(d) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Engine Certification Office. The request should be forwarded through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Engine Certification Office. NOTE: Information concerning the existence of approved alternative methods of compliance with this airworthiness directive, if any, may be obtained from the Engine Certification Office.
(e) Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate the airplane to a location where the requirements of this AD can be accomplished.
(f) The rework and reidentification shall be done in accordance with the following Textron Lycoming service bulletins:
Document No.
Pages
Revision
Date
ALF502R 72-270
1-4
1
March 31, 1992
5
Original
June 28, 1991
6-7
1
March 31, 1992
8-10
Original
June 28, 1991
Total pages: 10
ALF502L 72-270
1-13
Original
April 30, 1993
Total pages: 13
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 Textron Lycoming, 550 Main Street, Stratford, Connecticut 06497. Copies may be inspected at the FAA, New England Region, Office of the Assistant Chief Counsel, 12 New England Executive Park, Burlington, MA; or at the Office of the Federal Register, 800 North Capitol Street NW., suite 700, Washington, DC.
(g) This amendment becomes effective on October 4, 1993.