[Federal Register Volume 66, Number 120 (Thursday, June 21, 2001)]
[Proposed Rules]
[Pages 33214-33215]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-15574]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 90-ANE-25-AD]


Airworthiness Directives; General Electric Company (GE) CF6-45 
and CF6-50 Series Turbofan Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Proposed rule; withdrawal.

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SUMMARY: This action withdraws a notice of proposed rulemaking (NPRM) 
that proposed to revise an existing airworthiness directive (AD), 
applicable to GE CF6-45 and CF6-50 series turbofan engines. That action 
would have revised an existing AD to require the same inspections on 
reworked high pressure compressor (HPC) rear shafts as those HPC rear 
shafts covered by the current amendment. That proposal was prompted by 
the need to ensure that the additional reworked HPC rear shafts receive 
the same inspections as part numbers covered by the current amendment. 
Since that NPRM was issued, the FAA has determined that the repetitive 
inspections of reworked HPC rear shafts will instead be incorporated 
into the final rule, AD 2001-12-20, for a new design HPC air duct. 
Accordingly, the proposed rule is withdrawn.

FOR FURTHER INFORMATION CONTACT: Karen Curtis, Aerospace Engineer, 
Engine Certification Office, FAA, Engine and Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803; telephone (781) 238-
7192; fax (781) 238-7199.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to revise an existing AD, 
applicable to GE CF6-45 and CF6-50 series turbofan engines, was 
published in the Federal Register on October 12, 2000 (65 FR 60597). 
The proposed rule would have revised AD 91-10-03, R1, to add HPC rear 
shaft rework P/N's to the AD. That action was prompted by the need to 
ensure that the additional HPC rear shafts receive the same inspections 
as part numbers covered by the current amendment. The proposed actions 
were intended to detect and replace cracked HPC rear shafts, which, if 
not replaced, could lead to an uncontained engine failure.
    The FAA received a comment that notes that a new effective date of 
the AD revision could be misconstrued and result in parts continuing in 
service without the required inspections, for longer than originally 
intended by the current AD.
    The FAA agrees. Upon further consideration, the FAA has determined 
that the proposed addition of repetitive inspections of reworked HPC 
rear shafts will instead be incorporated into the final rule for a new 
design HPC air duct. The final rule for the new design air duct, AD 
2001-12-20, requires that existing HPC rear shafts be reworked for 
compatibility with new design air ducts, inspected at the time of 
rework, and repetitively inspected at specified

[[Page 33215]]

intervals. As a result, revising the existing AD is no longer required. 
Accordingly, the proposed rule is hereby withdrawn.
    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 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 90-ANE-25-
AD, published in the Federal Register on October 12, 2000, (65 FR 
60597), is withdrawn.

    Issued in Burlington, Massachusetts, on June 14, 2001.
Robert J. Ganley,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 01-15574 Filed 6-20-01; 8:45 am]
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