Airworthiness directives: Pratt & Whitney,

[Federal Register: September 23, 1999 (Volume 64, Number 184)]

[Proposed Rules]

[Page 51483-51484]

From the Federal Register Online via GPO Access [wais.access.gpo.gov]

[DOCID:fr23se99-26]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NE-32-AD]

RIN 2120-AA64

Airworthiness Directives; Pratt & Whitney JT8D-200 Series Turbofan Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

SUMMARY: This document proposes the adoption of a new airworthiness directive (AD) that is applicable to Pratt & Whitney JT8D-200 series turbofan engines. This proposal would require initial and repetitive fluorescent magnetic particle inspections or fluorescent penetrant inspections of the combustion chamber outer case (CCOC) for cracks, and, if necessary, replacement with serviceable parts. Also, this AD would require a one-time boss material verification, and, if necessary, replacement with serviceable parts. Finally, this AD would require replacement of CCOCs with welded-on bosses with improved, one-piece CCOCs. Installation of the one-piece CCOC would constitute terminating action to the inspection requirements of this AD. This proposal is prompted by reports of fatigue cracks originating at the weld joining the drain boss to the CCOC. The actions specified by the proposed AD are intended to prevent CCOC cracks, which could result in an uncontained engine failure and damage to the airplane.

DATES: Comments must be received by November 22, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), New England Region, Office of the Regional Counsel, Attention: Rules Docket No. 99-NE-32-AD, 12 New England Executive Park, Burlington, MA 01803-5299. Comments may also be sent via the Internet using the following address: ``9__ane__adcomment@faa.gov''. 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 referenced in the proposed rule may be obtained from Pratt & Whitney, 400 Main St., East Hartford, CT 06108; telephone (860) 565-6600, fax (860) 565-4503. This information may be examined at the FAA, New England Region, Office of the Regional Counsel, 12 New England Executive Park, Burlington, MA.

FOR FURTHER INFORMATION CONTACT: Chris Spinney, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803-5299; telephone (781) 238-7175, fax (781) 238-7199.

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 filedin 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 99-NE-32-AD.'' 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 Regional Counsel, Attention: Rules Docket No. 99-NE-32-AD, 12 New England Executive Park, Burlington, MA 01803-5299.

Discussion

The Federal Aviation Administration (FAA) has received reports of combustion chamber outer case (CCOC) cracks on Pratt & Whitney (PW) JT8D-209, -217, -217A, -217C, and -219 series turbofan engines. In one incident, a PW JT8D-219 engine installed on a McDonnell Douglas MD-80 series aircraft suffered an uncontained engine failure soon after takeoff, sustaining substantial damage to the engine cowl with some minor damage to the fuselage. The investigation revealed fatigue cracks originating at the weld joining a drain boss to the combustion chamber outer case (CCOC), which subsequently ruptured. This condition, if not corrected, could result in CCOC cracks, which could result in an uncontained engine failure and damage to the airplane.

Service Documents

The FAA has reviewed and approved the technical contents of: PW Alert Service Bulletin (ASB) No. A6359, Revision 1, dated July 30, 1999, that describes procedures for fluorescent magnetic particle inspections (FMPI) or fluorescent penetrant inspections (FPI) of certain CCOC bosses for cracks, and a one-time boss material verification of certain CCOCs identified by serial number (S/N); and PW Service Bulletin (SB) No. 6291, dated July 9, 1997, that describes procedures for replacement of CCOCs with welded-on bosses with improved, one-piece CCOCs.

Proposed Actions

Since an unsafe condition has been identified that is likely to exist or develop on other engines of this same type design, the proposed AD would require initial and repetitive FMPI or FPI of the certain CCOC bosses for cracks, and, if necessary, replacement with serviceable parts. Also, this AD would require a one-time boss material

[[Page 51484]]

verification of certain CCOCs identified by S/N, and, if necessary, replacement with serviceable parts. Finally, this AD would require replacement of CCOCs with welded-on bosses with improved, one-piece CCOCs. Installation of the one-piece CCOC would constitute terminating action to the inspection requirements of this AD. The actions would be required to be accomplished in accordance with the service documents described previously.

Economic Analysis

There are approximately 2,624 engines of the affected design in the worldwide fleet. The FAA estimates that 1,280 engines installed on aircraft of U.S. registry would be affected by this proposed AD, that it would take approximately 2.5 work hours per engine to accomplish the proposed inspections and that the average labor rate is $60 per work hour. Required parts would cost approximately $42,320 per engine. Based on these figures, the total cost impact of the proposed AD on U.S. operators is estimated to $54,361,600.

Regulatory Impact

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:

    Pratt & Whitney: Docket No. 99-NE-32-AD.

    Applicability: Pratt & Whitney (PW) JT8D-209, -217, -217A, - 217C, and -219 series turbofan engines with combustion chamber outer case (CCOC), part numbers (P/Ns) 5000238-01, 797707, 807684, and 815830 installed. These engines are installed on but not limited to McDonnell Douglas MD-80 series airplanes.

    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 (e) 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 CCOC cracks, which could result in an uncontained engine failure and damage to the airplane, accomplish the following:

    Inspections

    (a) Perform initial and repetitive fluorescent magnetic particle inspections (FMPI) or fluorescent penetrant inspections (FPI) of drain bosses and Ps4 bosses of the CCOC for cracks, and, if necessary replace with serviceable parts, in accordance with the procedures and intervals specified in paragraph 1.A. of the Accomplishment Instructions of PW Alert Service Bulletin (ASB) No. A6359, Revision 1, dated July 30, 1999.

    (b) For CCOCs listed by serial number (S/N) in Table 3 of PW ASB No. A6359, Revision 1, dated July 30, 1999, inspect for proper Ps4 and drain boss material, and replace, if necessary, with serviceable parts, in accordance with the procedures and intervals specified in paragraph 1.B. of the Accomplishment Instructions of PW ASB No. A6359, Revision 1, dated July 30, 1999.

    Terminating Action

    (c) At the next part accessibility after the effective date of this AD when the CCOC has accumulated cycles-in-service greater than the initial inspection threshold specified in table 1 of PW ASB A6359, Revision 1, dated July 30, 1999, replace the CCOC with a one- piece machined CCOC assembly, part number (P/N) 815556, in accordance with PW Service Bulletin (SB) No. 6291, dated July 9, 1997. Installation of an improved, one-piece CCOC, P/N 815556, constitutes terminating action to the inspections required by this AD.

    Definition

    (d) For the purpose of this AD, part accessibility is defined as an engine disassembly in which the CCOC is removed from the engine.

    (e) 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. Operators shall submit their request through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Engine Certification Office.

    Note 2: Information concerning the existence of approved alternative methods of compliance with this airworthiness directive, if any, may be obtained from the Engine Certification Office.

    (f) 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 September 16, 1999. Donald E. Plouffe, Acting Manager, Engine and Propeller Directorate, Aircraft Certification Service.

    [FR Doc. 99-24788Filed9-22-99; 8:45 am]

    BILLING CODE 4910-13-P

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