Airworthiness Directives; AlliedSignal Inc. TPE331 Series Turboprop and TSE331 Turboshaft Engines

[Federal Register Volume 62, Number 147 (Thursday, July 31, 1997)] [Proposed Rules] [Pages 40985-40987] From the Federal Register Online via the Government Publishing Office [www.gpo.gov] [FR Doc No: 97-20193]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-ANE-13] RIN 2120-AA64

Airworthiness Directives; AlliedSignal Inc. TPE331 Series Turboprop and TSE331 Turboshaft Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new 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. This proposal would require replacement or radiographic inspection, and replacement , if necessary, of certain third stage turbine stators with serviceable parts. This proposal 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 the proposed 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.

DATES: Comments must be received by September 29, 1997.

ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), New England Region, Office of the Assistant Chief Counsel, Attention: Rules Docket No. 97-ANE-13, 12 New England Executive Park, Burlington, MA 01803-5299. Comments may also be sent via the Internet using the following address: ``9-ad- [email protected]''. Comments sent via the Internet must contain the docket number in the subject line. Comments may be inspected at this location between 8:00 a.m. and 4:30 p.m., Monday through Friday, except Federal holidays. The service information on AlliedSignal Service Bulletin No. TPE331-A72-0861, Revision 2, dated April 23, 1997, referenced in the proposed rule 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. The service information on National Flight Services Service Bulletin No. NF-TPE331- A72-10961, dated April 28, 1997, referenced in the proposed rule 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. This information may be examined at the FAA, New England Region, Office of the Assistant Chief Counsel, 12 New England Executive Park, Burlington, MA.

FOR FURTHER INFORMATION CONTACT: Joseph Costa, Aerospace Engineer, Los Angeles Aircraft Certification Office, FAA, Transport Airplane Directorate, 3960 Paramount Blvd., Lakewood, CA 90712-4137; telephone (562) 627-5246; fax (562) 627-5210.

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in the making of the proposed rule by submitting such written data, views, or arguments as they may desire. Communications should identify the rules docket number and be submitted in triplicate to the address specified above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this notice may be changed in light of the comments received. Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed rule. All comments submitted will be available, both before and after the closing date for comments, in the rules docket for examination by interested persons. A report summarizing each FAA-public contact concerned with the substance of this proposal will be filed in the rules docket. Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this notice must submit a self-addressed, stamped postcard on which the following statement is made: ``Comments to Docket Number 97-ANE-13.'' The postcard will be date stamped and returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this NPRM by submitting a request to the FAA, New England Region, Office of the Assistant Chief Counsel, Attention: Rules Docket No. 97-aNE-13, 12 New England Executive Park, Burlington, MA 01803-5299.

Discussion

The Federal Aviation Administration (FAA) has received a report of a third stage turbine stator outer band weld that cracked on an AlliedSignal Inc. Model TPE331-5 turboprop engine. This weld, removed from service in January 1996 after the crack was discovered during turbine maintenance, had passed a one-time radiographic inspection for unacceptable weld penetration and thermal fatigue cracking required by AD 87-19-02. While AD 87-19-02 was

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superseded by AD 93-05-09, the requirement for a one-time radiographic inspection of the outer band weld for cracks was carried forward in to AD 93-05-09. The FAA determined that cracking initiated due to inadequate outer band butt weld penetration between the outer sheet metal ring and the nozzle casting. The FAA also determined that some radiographic films of unacceptable outer band welds may possibly have been misread by AlliedSignal Inc. In addition, numerous radiographic films are no longer on file at AlliedSignal Inc., and therefore reexamination of radiographic films of other welds is impossible. AlliedSignal Inc. no longer reads radiographic films; operators may use radiographic inspection in accordance with this AD as an alternate method of compliance with the radiographic inspection requirement of paragraph (h) of AD 93-05-09. Inadequate weld penetration could lead to fatigue cracking, shifting aft, and third stage turbine stator contact with the third stage turbine rotor. This condition, if not corrected, could result in third stage turbine wheel separation, which could result in an uncontained engine failure and damage to the aircraft. The FAA has reviewed and approved the technical contents of National Flight Services Service Bulletin (SB) No. NF-TPE331-A72-10961, dated April 28, 1997, that provides a list by serial number of third stage turbine stators not affected by this AD and describes procedures for the reinspection for unacceptable weld penetration and thermal fatigue cracking in third stage turbine stators initially inspected by AlliedSignal Inc.; and AlliedSignal Inc. SB No. TPE331-A72-0861, Revision 2, dated April 23, 1997, that describes procedures for replacing affected third stage turbine stators with redesigned serviceable stators. Since an unsafe condition has been identified that is likely to exist or develop on other products of this same type design, the proposed AD would require replacement of certain third stage turbine stators or radiographic inspection, and replacement, if necessary, with serviceable parts. The actions would be required to be accomplished in accordance with the SBs described previously. 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 would be affected by this proposed AD. The FAA estimates that 210 engines would require unscheduled replacement, that it would take approximately 40 work hours per engine to accomplish the proposed actions, and that the average labor rate is $60 per work hour. Required parts would cost approximately $6,500 per engine. Approximately 350 engines would require replacement during hot section inspection, which would take approximately 2 work hours per engine, with a parts cost of $6,500. Approximately 14 engines would require unscheduled inspection, which would take approximately 50 work hours to accomplish, with a parts cost of $1,500. Approximately 21 engines would require inspection during hot section inspection, which would take approximately 10 work hours to accomplish, with zero parts cost. Approximately 35 engines would require unscheduled inspection and replacement, which would take approximately 50 work hours to accomplish, with a $6,500 parts cost. Approximately 70 engines would require inspection and replacement during hot section inspection, which would 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 proposed AD on U.S. operators is estimated to be $4,986,100. The regulations proposed herein would 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 proposal would not have sufficient federalism implications to warrant the preparation of a Federalism Assessment. For the reasons discussed above, I certify that this proposed regulation (1) Is not a ``significant regulatory action'' under Executive Order 12866; (2) is not a ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) if promulgated, 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 copy of the draft regulatory evaluation prepared for this action is contained in the rules docket. A copy of it may be obtained by contacting the rules docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend 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.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by adding the following new airworthiness directive: AlliedSignal Inc.: Docket No. 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 Service Bulletin (SB) 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

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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 SB 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 SB 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 Removal schedule paragraph (b) or AD 93-05-09 paragraph (h) ------------------------------------------------------------------------ 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 SB No. NF-TPE331-A72-10961, dated April 28, 1997; or replace with a serviceable assembly in accordance with the Accomplishment Instructions of AlliedSignal Inc. SB 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 safety may 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.

Issued in Burlington, Massachusetts, on July 8, 1997. Ronald L. Vavruska, Acting Manager, Engine and Propeller Directorate, Aircraft Certification Service. [FR Doc. 97-20193 Filed 7-30-97; 8:45 am] BILLING CODE 4910-13-U