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[Federal Register Volume 81, Number 37 (Thursday, February 25, 2016)]
[Proposed Rules]
[Page 9367]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2016-03693]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2011-0254; Directorate Identifier 2010-NM-180-AD]
RIN 2120-AA64

Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Proposed rule; withdrawal.

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SUMMARY: The FAA withdraws a notice of proposed rulemaking (NPRM) that 
proposed a new airworthiness directive (AD), which would have applied 
to certain The Boeing Company Model 737-600, -700, -700C, -800, -900, 
and -900ER series airplanes. For certain airplanes, the NPRM would have 
required a one-time inspection for damage of the hydraulic actuator rod 
ends and actuator attach fittings on the thrust reversers, and repair 
or replacement if necessary. For all airplanes, the NPRM would have 
required repetitive inspections for damage of the hydraulic actuator 
rod ends, attach bolts, and nuts; repetitive inspections for damage of 
fitting assemblies, wear spacers, and actuator attach fittings on the 
thrust reverser; repetitive measurements of the wear spacer; and 
corrective actions if necessary. Since the NPRM was issued, the 
manufacturer notified us that an assumption regarding a failure mode of 
the rod ends or attachment fittings for the thrust reverser actuator 
used in the original safety assessment was incorrect. A new safety 
analysis was conducted and we determined that this issue is no longer a 
safety concern. Accordingly, the NPRM is withdrawn.

DATES: As of February 25, 2016, the proposed rule, which was published 
in the Federal Register on March 22, 2011 (76 FR 15864), is withdrawn.

ADDRESSES: You may examine the AD docket on the Internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2011-
0254; or in person at the Docket Management Facility between 9 a.m. and 
5 p.m., Monday through Friday, except Federal holidays. The AD docket 
contains this AD action, the NPRM (76 FR 15864, March 22, 2011), the 
regulatory evaluation, any comments received, and other information. 
The address for the Docket Office (telephone 800-647-5527) is the 
Docket Management Facility, U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE., Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: Tak Kobayashi, Aerospace Engineer, 
Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification 
Office, 1601 Lind Avenue SW., Renton, WA 98057-3356; phone: 425-917-
6499; fax: 425-917-6590; email: Takahisa.Kobayashi@faa.gov.

SUPPLEMENTARY INFORMATION:

Discussion

    We proposed to amend part 39 of the Federal Aviation Regulations 
(14 CFR part 39) with a notice of proposed rulemaking (NPRM) for a new 
AD for certain The Boeing Company Model 737-600, -700, -700C, -800, -
900, and -900ER series airplanes. The NPRM published in the Federal 
Register on March 22, 2011 (76 FR 15864) (``the NPRM''). For certain 
airplanes, the NPRM would have required a one-time inspection for 
damage of the hydraulic actuator rod ends and actuator attach fittings 
on the thrust reversers, and repair or replacement if necessary. For 
all airplanes, the NPRM would have required repetitive inspections for 
damage of the hydraulic actuator rod ends, attach bolts, and nuts; 
repetitive inspections for damage of fitting assemblies, wear spacers, 
and actuator attach fittings on the thrust reverser; repetitive 
measurements of the wear spacer; and corrective actions if necessary.
    The NPRM was prompted by reports of in-service damage of the 
attachment fittings for the thrust reverser actuator. The proposed 
actions were intended to detect and correct such damage, which could 
result in actuator attach fitting failure, loss of the thrust reverser 
auto restow function, and consequent loss of control of the airplane.

Actions Since NPRM Was Issued

    Since we issued the NPRM, the manufacturer has notified us that an 
assumption regarding a failure mode of the attachment fittings for the 
thrust reverser actuator used in the original safety assessment was 
incorrect. It was originally assumed that all hydraulic actuators 
attached to the thrust reverser have the failure mode (failure of the 
hydraulic actuator rod end or attach fitting due to severe wear-out) 
addressed in the NPRM. Based on field reports and design review, the 
manufacturer found that certain hydraulic actuators do not have this 
failure mode. Based on this new manufacturer finding, a new safety 
analysis was conducted and we determined that this issue is no longer a 
safety concern.

FAA's Conclusions

    Upon further consideration, we have determined that the safety 
concern identified in the NPRM does not affect The Boeing Company Model 
737-600, -700, -700C, -800, -900, and -900ER series airplanes 
identified in the NPRM. Accordingly, the NPRM is withdrawn.
    Withdrawal of the NPRM does not preclude the FAA from issuing 
another related action or commit the FAA to any course of action in the 
future.

Regulatory Impact

    Since this action only withdraws an NPRM, 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, Incorporation by 
reference, Safety.

The Withdrawal

    Accordingly, we withdraw the NPRM, Docket No. FAA-2011-0254, 
Directorate Identifier 2010-NM-180-AD, which was published in the 
Federal Register on March 22, 2011 (76 FR 15864).

    Issued in Renton, Washington, on February 15, 2016.
Michael Kaszycki,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2016-03693 Filed 2-24-16; 8:45 am]
BILLING CODE 4910-13-P
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