Document ID: FAA-2007-0222-0001
Agency: faa
Document Type: Rule
Title: Airworthiness Directives; Boeing Model 747 Series Airplanes Powered by General Electric (GE) CF6-45/50, Pratt and Whitney (P&W) JT9D- 70, or JT9D-7 Series Engines
Posted Date: 2007-11-15T05:00Z

[Federal Register: November 15, 2007 (Volume 72, Number 220)]
[Proposed Rules]               
[Page 64171-64172]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr15no07-25]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001-NM-40-AD]
RIN 2120-AA64

 
Airworthiness Directives; Boeing Model 747 Series Airplanes 
Powered by General Electric (GE) CF6-45/50, Pratt & Whitney (P&W) JT9D-
70, or JT9D-7 Series 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 a new airworthiness directive (AD), applicable to certain 
Boeing Model 747 series airplanes powered by GE CF6-45/50, P&W JT9D-70, 
or JT9D-7 series engines. That action would have required repetitive 
inspections to find cracks and broken fasteners of the inboard and 
outboard nacelle struts of the rear engine mount bulkhead, and repair, 
if necessary. For certain airplanes, that action would have provided 
for an optional terminating modification for the inspections of the 
outboard nacelle struts. Since the issuance of the NPRM, the Federal 
Aviation Administration (FAA) has received new data of other issues 
related to the unsafe condition. The data include many new reports of 
additional web and frame cracks and sheared attachment fasteners, and 
reports of cracks on the outboard struts of airplanes not identified in 
the applicability of the NPRM, in addition to the comments received for 
the NPRM. We have determined from these data that the corrective 
actions required by the NPRM are inadequate for addressing the 
identified unsafe condition. Accordingly, the proposed rule is 
withdrawn.

FOR FURTHER INFORMATION CONTACT: Tamara Anderson, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 
917-6421; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to add a new airworthiness 
directive (AD), applicable to certain Boeing Model 747 series airplanes 
powered by General Electric (GE) CF6-45/50, Pratt & Whitney (P&W) JT9D-
70, or JT9D-7 series engines, was published as a notice of proposed 
rulemaking (NPRM) in the Federal Register on January 9, 2002 (67 FR 
1167). The proposed rule would have required repetitive inspections to 
find cracks and broken fasteners of the inboard and outboard nacelle 
struts of the rear engine mount bulkhead, and repair, if necessary. For 
certain airplanes, the proposed rule would have provided for an 
optional terminating modification for the inspections of the outboard 
nacelle struts. That action was prompted by reports indicating that 
fatigue cracking of the inboard and outboard nacelle struts of the rear 
engine mount bulkhead was found. The proposed actions were intended to 
find and fix cracks and broken fasteners of the inboard and outboard 
nacelle struts, which could result in possible loss of the bulkhead 
load path and consequent separation of the engine from the airplane.

Actions That Occurred Since the NPRM Was Issued

    Since the issuance of the NPRM, the Federal Aviation Administration 
(FAA) has received new data of other issues related to the unsafe 
condition. The data include many new reports of additional web and 
frame cracks and sheared attachment fasteners, and reports of cracks on 
the outboard struts of airplanes not identified in the applicability of 
the NPRM, in addition to the comments received for the NPRM. We have 
determined from these data that the corrective actions required by the 
NPRM are inadequate for addressing the identified unsafe condition. 
Therefore, we are issuing a new rulemaking to adequately address the 
identified unsafe condition.

FAA's Conclusions

    Upon further consideration, the FAA has determined that the 
corrective actions required by the NPRM are inadequate for addressing 
the identified unsafe condition. Accordingly, the proposed rule is 
hereby withdrawn.
    Withdrawal of this NPRM constitutes only such action, and does not 
preclude the agency from issuing another action in the future, nor does 
it commit the agency to any course of action in the future.

Regulatory Impact

    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).

[[Page 64172]]

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Withdrawal

    Accordingly, the notice of proposed rulemaking, Docket 2001-NM-40-
AD, published in the Federal Register on January 9, 2002 (67 FR 1167), 
is withdrawn.

    Issued in Renton, Washington, on November 7, 2007.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
 [FR Doc. E7-22329 Filed 11-14-07; 8:45 am]

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