[Federal Register Volume 59, Number 211 (Wednesday, November 2, 1994)]
[Proposed Rules]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-27112]


[[Page Unknown]]

[Federal Register: November 2, 1994]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 92-ASW-37]

 

Airworthiness Directives; Sikorsky Aircraft Model S-76B 
Helicopters

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 a new airworthiness directive (AD), applicable to 
Sikorsky Aircraft Model S-76B helicopters. That action would have 
limited the applicability of the inspections of the left and right 
engine input drive shaft assemblies (shaft assemblies) for loose 
balance weights or cracks to those shaft assemblies of original (or 
initial) design only, and would have excluded redesigned shaft 
assemblies from those inspections. Since the issuance of the NPRM, the 
FAA has received a report of a fatigue crack in a redesigned shaft 
assembly indicating a need to continue the existing inspections of the 
redesigned shaft assembly. Accordingly, the proposed rule is withdrawn.

FOR FURTHER INFORMATION CONTACT: Mr. Terry Fahr, Aerospace Engineer, 
Boston Aircraft Certification Office, ANE-153, FAA, Engine and 
Propeller Directorate, 12 New England Executive Park, Burlington, 
Massachusetts 01803, telephone (617) 238-7155, fax (617) 238-7199.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to supersede an existing 
airworthiness directive (AD), applicable to Sikorsky Aircraft Model S-
76B helicopters, was published in the Federal Register on November 2, 
1992 (57 FR 49431). The proposed rule would have limited the 
applicability of AD 91-19-02 by requiring initial and repetitive 25 
hours time-in-service inspections of the shaft assemblies of original 
(or initial) design only, excluding the redesigned shaft assemblies 
from the inspections. That action was prompted by the introduction of a 
redesigned shaft assembly that was designed to eliminate the cause of 
cracks in the original shaft assemblies. The proposed actions were 
intended to prevent failure of certain shaft assemblies and subsequent 
loss of power to the helicopter rotor system.
    Since the issuance of that NPRM, the FAA has received a report of a 
fatigue crack in a redesigned shaft assembly. Therefore, the FAA issued 
Priority Letter AD 93-1-05 on June 4, 1993, to require inspections of 
the redesigned shaft assemblies at intervals not to exceed 6 hours 
time-in-service from the last inspection.
    Upon further consideration, the FAA has determined that the 
proposed rule to exclude redesigned shaft assemblies from the AD 
inspections is no longer appropriate. 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 92-ASW-37, 
published in the Federal Register on November 2, 1992, (57 FR 49431), 
is withdrawn.

    Issued in Fort Worth, Texas, on October 26, 1994.
Eric Bries,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 94-27112 Filed 11-1-94; 8:45 am]
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