AD 98-04-15

This amendment adopts a new airworthiness directive (AD), applicable to AlliedSignal Inc., (formerly Garrett Engine Division, Garrett Turbine Engine Company and AiResearch Manufacturing Company of Arizona) TPE331 series turboprop and TSE331 turboshaft engines, that requires replacement or radiographic inspection, and replacement, if necessary, of certain third stage turbine stators with serviceable parts. This amendment is prompted by a report of an outer band weld that cracked subsequent to a radiographic inspection required by a previous AD. The actions specified by this AD are intended to prevent third stage turbine wheel separation due to thermal fatigue cracking and shifting of the third stage turbine stator, which could contact the third stage turbine wheel and result in an uncontained engine failure and damage to the aircraft.

Final rule.

98-04-15 AlliedSignal Inc.: Amendment 39-10327. Docket 97-ANE-13.
Applicability: AlliedSignal Inc., (formerly Garrett Engine Division, Garrett Turbine Engine Company and AiResearch Manufacturing Company of Arizona) Model TPE331-1, -2, -2UA, -3U, -3UW, -5, -5A, -5AB, -5B, -6, and -6A turboprop and TSE331-3U turboshaft engines with third stage turbine stators, Part Number (P/N) 868379-3, except those engines with turbine stators listed by Serial Number (S/N) in Table 1 of the National Flight Services Alert Service Bulletin (ASB) No. NF-TPE331-A72-10961, dated April 28, 1997. 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.
Note 1: This airworthiness directive (AD) applies to each engine identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For engines that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (g) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.
Compliance: Required as indicated, unless accomplished previously.
To prevent third stage turbine wheel separation due to fatigue cracking and shifting of the third stage turbine stator, which could result in an uncontained engine failure and damage to the aircraft, accomplish the following:
(a) For engines with third stage turbine stators with S/Ns listed in Table 1 of National Flight Services ASB No. NF-TPE331-A72-10961, dated April 28, 1997, no action is required.
(b) For engines with third stage turbine stators with S/Ns not listed in Table 1 of National Flight Services ASB No. NF-TPE331-A72-10961, dated April 28, 1997, remove the unserviceable third stage turbine stator assembly in accordance with the applicable engine maintenance manual and the following schedule:

Third Stage Turbine Stator Cycles in Service (CIS) Since Radiographic Inspection in Accordance with AD 87-19-02 paragraph (b) or AD 93-05-09 paragraph (h).
Removal Schedule
Unknown CIS since inspection
remove within 600 CIS after the effective date of this AD, at next access, or prior to March 31, 2002, whichever occurs first
2200 or more CIS since inspection
remove within 600 CIS after the effective date of this AD, at next access, or prior to March 31, 2002, whichever occurs first
Less than 2200 CIS since inspection
remove prior to accumulating 2,800 CIS, at next access, or prior to March 31, 2002, whichever occurs first

(c) For the purpose of this AD, the next access to the third stage stator assembly is defined as disassembly of the turbine beyond the removal of the third stage rotor.
Note 2: This AD does not supersede AD 93-05-09. The removal schedule in paragraph (b) of this AD does not affect the requirements of AD 93-05-09.
(d) For the purpose of determining third stage turbine stator removal under paragraph (b) of this AD, third stage turbine stator hours time in service (TIS) may be converted to CIS since inspection by multiplying by 1.5 the number of hours since radiographic inspection in accordance with paragraph (b) of AD 87-19-02 or paragraph (h) of AD 93-05-09.
(e) For third stage turbine stator assemblies removed in accordance with paragraph (b) of this AD, accomplish either a radiographic inspection for inadequate weld penetration and fatigue cracking, and, if necessary, replace with a serviceable assembly in accordance with the Accomplishment Instructions of National Flight Services ASB No. NF-TPE331-A72-10961, dated April 28, 1997; or replace with a serviceable assembly in accordance with the Accomplishment Instructions of AlliedSignal Inc. ASB No. TPE331-A72-0861, Revision 2, dated April 23, 1997. Accomplishing the radiographic inspection required by this paragraph constitutes compliance with the radiographic inspection requirement of paragraph (h) of AD 93-05-09.
(f) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safetymay be used if approved by the Manager, Los Angeles Aircraft Certification Office. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Los Angeles Aircraft Certification Office.
Note 3: 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.
(g) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the aircraft to a location where the requirements of this AD can be accomplished.
(h) The actions required by this AD shall be done in accordance with the following ASBs:

Document No
Pages
Revision
Date
National Flight Services ASB No.
NF-TPE331-A72-
10961
1-11
Original
April 28, 1997
Total Pages: 11.

AlliedSignal Inc. ASB No. TPE331-A72-0861
1
2
3-5
6
7
8
2
1
2
1
2
1
April 23, 1997
October 25, 1996
April 23, 1997
October 25, 1996
April 23, 1997
October 24, 1996
Total Pages: 8.

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 of AlliedSignal Service Bulletin No. TPE331-A72-0861, Revision 2, dated April 23, 1997, may be obtained from AlliedSignal Aerospace, Attn.: Data Distribution, M/S 64-3/2101-201, P.O. Box 29003, Phoenix, AZ 85038-9003; telephone (602) 365-2493, fax (602) 365-5577. Copies of National Flight Services ASB No. NF-TPE331-A72-10961, dated April 28, 1997, may be obtained from either National Flight Services, Inc. 10971 E. Airport Services Road, Toledo Express Airport, Swanton, OH 43558; telephone (419) 865-2311, fax (419) 867-4224, or http://www.natfs.com, or National Flight Services of Arizona, Inc., 5170 W. Bethany Home Road, Glendale,AZ 85301; telephone (602) 931-1143, fax (602) 931-7264. Copies may be inspected at the FAA, New England Region, Office of the Regional 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.
(i) This amendment becomes effective on April 27, 1998.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an airworthiness directive (AD) that is applicable to AlliedSignal Inc., (formerly Garrett Engine Division, Garrett Turbine Engine Company and AiResearch Manufacturing Company of Arizona) TPE331 series turboprop and TSE331 turboshaft engines was published in the Federal Register on July 31, 1997 (62 FR 40985). That action proposed to require replacement of certain third stage turbine stators or radiographic inspection, and replacement, if necessary, with serviceable parts.
Interested persons have been afforded an opportunity to participate in the making of this amendment. No comments were received on the proposal or the FAA's determination of the cost to the public. The FAA has determined that air safety and the public interest require the adoption of the rule as proposed.
There are approximately 1,000 engines of the affected design in the worldwide fleet. The FAA estimates that 700 engines installed on aircraft of U.S. registry will be affected by this AD. The FAA estimates that 210 engines will require unscheduled replacement, that it will take approximately 40 work hours per engine to accomplish the required actions, and that the average labor rate is $60 per work hour. Required parts will cost approximately $6,500 per engine. Approximately 350 engines will require replacement during hot section inspection, which will take approximately 2 work hours per engine, with a parts cost of $6,500. Approximately 14 engines will require unscheduled inspection, which will take approximately 50 work hours to accomplish, with a parts cost of $1,500. Approximately 21 engines will require inspection during hot section inspection, which will take approximately 10 work hours to accomplish, with zero parts cost. Approximately 35 engines will require unscheduled inspection and replacement, which will take approximately 50 work hours to accomplish,with a $6,500 parts cost. Approximately 70 engines will require inspection and replacement during hot section inspection, which will take approximately 10 work hours to accomplish, with a $5,000 parts cost. The FAA has been informed by AlliedSignal Inc. that they will provide a redesigned third stage turbine stator assembly at a special program price and will pay for the labor to install this assembly. Based on these figures, without the special price program from the manufacturer, the total cost impact of the AD on U.S. operators is estimated to be $4,986,100.
The regulations adopted herein will not have substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government. Therefore, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.
For the reasons discussed above, I certify that this action (1) is not a "significant regulatory action" under Executive Order 12866; (2) is not a "significant rule" under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. A final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it may be obtained from the Rules Docket at the location provided under the caption "ADDRESSES." List of Subjects in 14 CFR Part 39
Air Transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.
Adoption of the Amendment
Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows: PART 39 - AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new airworthiness directive: