Airworthiness directives: Pratt & Whitney,

[Federal Register: October 12, 1999 (Volume 64, Number 196)]

[Proposed Rules]

[Page 55195-55196]

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

[DOCID:fr12oc99-33]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 95-ANE-57]

Airworthiness Directives; Pratt & Whitney JT9D Series Turbofan Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Proposed rule; withdrawal.

SUMMARY: This action withdraws a notice of proposed rulemaking (NPRM) that proposed a new airworthiness directive (AD), applicable to Pratt & Whitney JT9D series turbofan engines. That action would have superseded AD 96-25-10 by adding additional affected turbine exhaust case (TEC) assemblies eligible for modification, and adding an additional TEC modification compliance option. Since the issuance of the NPRM, the Federal Aviation Administration (FAA) determined that any additional TEC assemblies could be installed as a TEC modification compliance option through the alternate method of compliance (AMOC) procedure instead. Accordingly, the proposed rule is withdrawn.

FOR FURTHER INFORMATION CONTACT: Tara Goodman, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803-5299; telephone (781) 238-7130, fax (781) 238-7199.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to add a new airworthiness directive (AD) to supersede AD 96-25-10, amendment 39-9853 (61 FR 66892, December 19, 1996), applicable to Pratt & Whitney (PW) JT9D series turbofan engines, was published in the Federal Register on September 2, 1998 (63 FR 46712). The proposed rule would have added additional affected turbine exhaust case (TEC) assemblies that are eligible for modification, and added an additional TEC modification compliance option. That action was prompted by PW issuing Service Bulletin (SB) No. 6157, Revision 2, dated January 28, 1998, that lists by part number (P/N) additional affected TEC assemblies that are eligible for modification, and by PW providing an additional TEC modification compliance option in issuing PW SB No. 6320, dated February 5, 1998. The proposed actions were intended to prevent release of uncontained debris from the TEC following an internal engine failure, which can result in damage to the aircraft.

Since the issuance of that NPRM, the FAA reevaluated the proposed supersedure of AD 96-25-10. The current AD is applicable to certain PW JT9D engines and mandates a modification using specific TEC P/Ns listed in the SBs incorporated by reference. More recent revisions of the SBs referenced in the current AD offer the possibility of using TEC assembly P/Ns not included in the SBs incorporated into the current AD. The proposal sought to expand that list of TEC assembly P/Ns that would serve as compliance with the requirements of the current AD. The proposal, however, did not preserve the original compliance end date of the current AD. The FAA has determined, therefore, that rather than superseding the existing AD, the additional TEC assembly P/Ns may be considered approved alternate methods of compliance (AMOC) using the AMOC process specified in the current AD. This will preserve the current AD's compliance end-date for the modification.

Upon further consideration, the FAA has determined that superseding AD 96-25-10 is unnecessary. Accordingly the proposed rule is hereby withdrawn. AD 96-25-10 in its original form, remains in effect.

Withdrawal of this notice of proposed rulemaking constitutes only such action, and does not preclude the agency from issuing another notice in the future, nor does it commit the agency to any course of action in the future.

Since this action only withdraws a notice of proposed rulemaking, it is neither a proposed nor a final rule and therefore, is not covered under Executive Order 12866, the Regulatory Flexibility Act, or DOT Regulatory

[[Page 55196]]

Policies and Procedures (44 FR 11034, February 26, 1979).

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Safety.

The Withdrawal

Accordingly, the notice of proposed rulemaking, Docket 95-ANE-57, published in the Federal Register on September 2, 1998, (63 FR 46712), is withdrawn.

Issued in Burlington, Massachusetts, on October 5, 1999. Diane Romanosky, Acting Manager, Engine and Propeller Directorate, Aircraft Certification Service.

[FR Doc. 99-26575Filed10-8-99; 8:45 am]

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