AD 93-05-09

93-05-09 ALLIED-SIGNAL INC., GARRETT ENGINE DIVISION: Amendment 39-8560. Docket No. 93-ANE-05. Supersedes AD 87-19-02, Amendment 39-5707, and priority letter AD 91-04-02, issued February 8, 1991. Applicability: Allied-Signal Inc., Garrett Engine Division, Model TPE331-1, -2, -2UA, -3U, -3UW, -5, -5A, -5AB, -5B, -6, and -6A turboprop and Model TSE331-3U turboshaft engines containing third stage turbine stator assemblies Part Number (P/N) 868379-1, -3, or -5. These engines are installed on but not limited to: Mitsubishi MU-2B series (MU-2 series); Construcciones Aeronauticas, S.A. (CASA) C-212 series; Fairchild SA226 series (Swearingen Merlin and Metro series); Prop-Jets, Inc. Model 400; Twin Commander 680 and 690 (Jetprop Commander); Rockwell Commander S-2R; Shorts Brothers and Harland, Ltd. SC7 (Skyvan); Dornier 228 series; Beech 18 and 45 series and Models JRB-6, 3N, 3NM, 3TM, and B100; Pilatus PC-6 series (Fairchild Porter and Peacemaker); De Havilland DH 104 series 7AXC (Dove); Ayres S-2R series; Grumman American G- 164 series; and Schweizer G-164 series airplanes; and Sikorsky S-55 series (Helitec Corp. S55T) helicopters. Compliance: Required as indicated, unless accomplished previously. To prevent an uncontained failure of the third stage turbine wheel, accomplish the following: (a) If the cycles in service (CIS) since new or rework of third stage turbine stator assemblies, P/N 868379-1 and -3, are unknown, convert hours time in service (TIS) to CIS by multiplying the hours TIS since new or rework upon receipt of this AD by 1.5 to get CIS since new or rework on the effective date of this AD. (b) Replace third stage turbine stator assemblies, P/N 868379-1 and -3, with new or reworked assemblies in accordance with the applicable Allied-Signal Inc., Garrett Engine Division, Engine Maintenance Manual, and the following schedule, based upon CIS:

CIS since New or Rework on the effective date of this AD Replacement Schedule CIS unknown Replace within 50 CIS after the effective date of this AD. 5500 or more CIS Replace within 50 CIS after the effective date of this AD. 4000 to 5499 CIS

Replace within 200 CIS after the effective date of this AD, but not more than 5550 CIS since new or rework, whichever occurs first. 3200 to 3999 CIS Replace within 400 CIS after the effective date of this AD, but not more than 4200 CIS since new or rework, whichever occurs first. Less than 3200 CIS Replace prior to accumulating 3600 CIS since new or rework.

(c) During access to the third stage turbine stator assembly as required in paragraph (b) of this AD, remark all third stage turbine stator assemblies P/N 868379-1 as third stage turbine stator assemblies P/N 868379- 3, in accordance with the Accomplishment Instructions of Garrett Turbine Engine Company Alert Service Bulletin (ASB) No. TPE/TSE-331-A72-0384, Revision 3, dated July 1, 1987, or ASB No. TPE/TSE-331-A72- 0384, Revision 4, dated September 4, 1987.(d) Thereafter, replace third stage turbine stator assemblies, P/N 868379-1 and -3, with new or reworked assemblies in accordance with the applicable Allied-Signal Inc., Garrett Engine Division, Engine Maintenance Manual, at intervals not to exceed 3600 CIS since new or rework. (e) Replace third stage turbine stator assemblies, P/N 868379-5, with new or reworked assemblies in accordance with the applicable Allied-Signal Inc., Garrett Engine Division, Engine Maintenance Manual, and the following schedule:

CIS since New or Rework on the effective date of this AD Replacement Schedule CIS unknown Replace within 50 CIS after the effective date of this AD. 900 or more CIS Replace within 50 CIS after the effective date of this AD. 450 to 899 CIS Replace within 150 CIS after the effective date of this AD, but not more than 950 CIS since new or rework, whichever occurs first. Less than 450 CIS Replace prior to accumulating 600 CIS since new or rework.

(f) Thereafter, replace third stage turbine stator assemblies, P/N 868379-5, with new or reworked assemblies in accordance with the applicable Allied-Signal Inc., Garrett Engine Division, Engine Maintenance Manual, at intervals not to exceed 600 CIS since new or rework. NOTE: Additional information regarding the replacement of the stator assembly can be obtained from Allied- Signal, Inc., Garrett Engine Division, ASB No. TPE331-A72-0861, dated November 19, 1992. (g) For the purposes of this AD, rework of the third stage turbine stator assembly must include installation of a new inner seal support. (h) Perform a one-time X-ray inspection of all third stage turbine stator assemblies, P/N 868379-1 and -3, for weld penetration in accordance with the following schedule and replace, if necessary, in accordance with the Accomplishment Instructions of Garrett Turbine Engine Company ASB No. TPE331-A72-0559, dated July 1, 1987, ASB No. TPE331-A72-0559, Revision 1, dated September 4, 1987, or ASB No. TPE331-A72-0559, Revision 2, dated January 15, 1988, except those third stage turbine stator assemblies listed by serial number in Table 1 of those ASB's:

Hours TIS since New on September 14, 1987 Inspection Schedule Unknown hours TIS Inspect within 200 hours TIS after September 14, 1987. 5001 or more hours TIS Inspect within 200 hours TIS after September 14, 1987. 4000 to 5000 hours TIS Inspect within 500 hours TIS after September 14, 1987, or prior to accumulating 5200 hours TIS since new, whichever occurs first. Less than 4000 hours TIS Inspect prior to accumulating 4500 hours TIS since new.

NOTE: September 14, 1987, is the effective date of AD 87-19-02. (i) An alternative method of compliance or adjustment of the initial compliance time that provides an acceptable level of safety may be used if approved by the Manager, Los Angeles Aircraft 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, Los Angeles Aircraft Certification Office. NOTE: Information concerning the existence of approved alternative methods of compliance with this airworthiness directive, if any, may be obtained from the Los Angeles Aircraft Certification Office. (j) Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate the aircraft to a location where the requirements of this AD can be accomplished. (k) The remarking and one-time x-ray inspection shall be done in accordance with the following Garrett Turbine Engine Company Alert Service Bulletins:

Document No. Pages Revision Date TPE/TSE331-A72-0384 total pages: 12 1-12 3 July 1, 1987 TPE/TSE331-A72-0384 1 4 September 4, 1987

2 3 July 1, 1987

3 4 September 4, 1987 total pages: 12 4-12 3 July 1, 1987

TPE331-A72-0559 total pages: 16 1-16 Original July 1, 1987

TPE331-A72-0559 1 1 September 4, 19872 Original July 1, 1987

3-4 1 September 4, 1987

5-6 Original July 1, 1987

7-14 1 September 4, 1987 total pages: 16 15-16 Original July 1, 1987

TPE331-A72-0559 1 2 January 15, 1988

2 Original July 1, 1987

3 1 September 4, 1987

4 2 January 15, 1988

5-6 Original July 1, 1987 total pages: 20 7-20 2 January 15, 1988

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 Garrett General Aviation Services Division, Distribution Center, 1944 East Sky Harbor Circle, Phoenix, Arizona 85034; telephone (602) 365-2548. Copies may be inspected at the FAA, New England Region, Office of the Assistant Chief Counsel, 12 New England Executive Park, Burlington, Massachusetts; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. (1) This amendment becomes effective on June 28, 1993, to all persons except those persons to whom it was made immediately effective by priority letter AD 93-05-09, issued March 8, 1993, which contained the requirements of this amendment.