Airworthiness Directives; Boeing Model 757 Series Airplanes

[Federal Register Volume 64, Number 220 (Tuesday, November 16, 1999)]
[Rules and Regulations]
[Pages 62109-62110]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-29471]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

RIN 2120-AA64
[Docket No. 99-NM-101-AD; Amendment 39-11417; AD 99-23-21]


Airworthiness Directives; Boeing Model 757 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to certain Boeing Model 757 series airplanes, that requires 
a modification of the reverse thrust lever assemblies and replacement 
of the spring bumper assemblies of the thrust reverser sleeves with new 
assemblies. This amendment is prompted by an FAA review of the thrust 
reverser system on all transport category airplanes including the 
Boeing Model 757 series airplane. The actions specified by this AD are 
intended to prevent operation with an energized sync lock or 
malfunctioning sleeve locking devices, which could result in the 
deployment of a thrust reverser in flight and subsequent reduced 
controllability of the airplane.

DATES: Effective December 21, 1999.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of December 21, 1999.

ADDRESSES: The service information referenced in this AD may be 
obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, 
Washington 98124-2207. This information may be examined at the Federal 
Aviation Administration (FAA), Transport Airplane Directorate, Rules 
Docket, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of 
the Federal Register, 800 North Capitol Street, NW., suite 700, 
Washington, DC.

FOR FURTHER INFORMATION CONTACT: Kathrine Rask, Aerospace Engineer, 
Propulsion Branch, ANM-140S, FAA, Transport Airplane Directorate, 
Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056; telephone (425) 227-1547; fax (425) 227-1181.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an airworthiness 
directive (AD) that is applicable to certain Boeing Model 757 series 
airplanes was published in the Federal Register on August 23, 1999 (64 
FR 45927). That action proposed to require a modification of the 
reverse thrust lever assemblies and replacement of the spring bumper 
assemblies of the thrust reverser sleeves with new assemblies.

Comments

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. No comments were submitted in response 
to the proposal or the FAA's determination of the cost to the public.

Conclusion

    The FAA has determined that air safety and the public interest 
require the adoption of the rule as proposed.

Cost Impact

    There are approximately 308 airplanes of the affected design in the 
worldwide fleet.
    The FAA estimates that the modification of the reverse thrust lever 
assemblies will be required to be accomplished on 169 U.S. registered 
airplanes. It will take approximately 8 work hours per airplane to 
accomplish the required modification at an average labor rate of $60 
per work hour. Required parts will cost approximately $29 per airplane. 
Based on these figures, the cost impact of this required modification 
on U.S. operators is estimated to be $86,021, or $509 per airplane.
    The FAA estimates that the replacement of the spring bumper 
assemblies will be required to be accomplished on 92 U.S. registered 
airplanes. It will take approximately 10 work hours per airplane to 
accomplish the required replacement at an average labor rate of $60 per 
work hour. Required parts will cost approximately

[[Page 62110]]

$5,178 per airplane. Based on these figures, the cost impact of this 
required replacement on U.S. operators is estimated to be $531,576, or 
$5,778 per airplane.
    The cost impact figures discussed above are based on assumptions 
that no operator has yet accomplished any of the requirements of this 
AD action, and that no operator would accomplish those actions in the 
future if this AD were not adopted.

Regulatory Impact

    The regulations adopted herein will not have substantial direct 
effects on the States, on the relationship between the national 
government and the States, or on the distribution of power and 
responsibilities among the various levels of government. Therefore, in 
accordance with Executive Order 12612, it is determined that this final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this action (1) is 
not a ``significant regulatory action'' under Executive Order 12866; 
(2) is not a ``significant rule'' under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979); and (3) will not have a 
significant economic impact, positive or negative, on a substantial 
number of small entities under the criteria of the Regulatory 
Flexibility Act. A final evaluation has been prepared for this action 
and it is contained in the Rules Docket. A copy of it may be obtained 
from the Rules Docket at the location provided under the caption 
ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends part 39 of 
the Federal Aviation Regulations (14 CFR part 39) as follows:

PART 39--AIRWORTHINESS DIRECTIVES

    1. The authority citation for part 39 continues to read as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

99-23-21  Boeing: Amendment 39-11417. Docket 99-NM-101-AD.

    Applicability: Model 757 series airplanes, as listed in Boeing 
Service Bulletin 757-76-0009, Revision 1, dated December 3, 1998, or 
Boeing Service Bulletin 757-78-0012, dated August 31, 1989; 
certificated in any category.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
modified, altered, or repaired in the area subject to the 
requirements of this AD. For airplanes that have been modified, 
altered, or repaired so that the performance of the requirements of 
this AD is affected, the owner/operator must request approval for an 
alternative method of compliance in accordance with paragraph (c) of 
this AD. The request should include an assessment of the effect of 
the modification, alteration, or repair on the unsafe condition 
addressed by this AD; and, if the unsafe condition has not been 
eliminated, the request should include specific proposed actions to 
address it.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent operation with an energized sync lock or 
malfunctioning sleeve locking devices, which could result in 
deployment of a thrust reverser in flight and subsequent reduced 
controllability of the airplane, accomplish the following:
    (a) For airplanes listed in Boeing Service Bulletin 757-76-0009, 
Revision 1, dated December 3, 1998: Within 2 years after the 
effective date of the AD, replace the reverse thrust switches and 
actuators with improved switches and actuators, and modify the 
reverse lever links and thrust control levers in accordance with the 
service bulletin.

    Note 2: Modifications accomplished prior to the effective date 
of this AD in accordance with Boeing Service Bulletin 757-76-0009, 
dated November 8, 1990, are considered acceptable for compliance 
with the applicable action specified in this amendment.
    (b) For airplanes listed in Boeing Service Bulletin 757-78-0012, 
dated August 31, 1989: Within 2 years after the effective date of 
the AD, replace the spring bumper assemblies of the thrust reverser 
sleeve with improved assemblies in accordance with the service 
bulletin.

Alternative Methods of Compliance

    (c) An alternative method of compliance or adjustment of the 
compliance time that provides an acceptable level of safety may be 
used if approved by the Manager, Seattle Aircraft Certification 
Office (ACO), FAA, Transport Airplane Directorate. Operators shall 
submit their requests through an appropriate FAA Principal 
Maintenance Inspector, who may add comments and then send it to the 
Manager, Seattle ACO.

    Note 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle ACO.

Special Flight Permits

    (d) Special flight permits may be issued in accordance with 
Secs. 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 
21.197 and 21.199) to operate the airplane to a location where the 
requirements of this AD can be accomplished.

Incorporation by Reference

    (e) The actions shall be done in accordance with Boeing Service 
Bulletin 757-76-0009, Revision 1, dated December 3, 1998, or Boeing 
Service Bulletin 757-78-0012, dated August 31, 1989, as applicable. 
This incorporation by reference was approved by the Director of the 
Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 
51. Copies may be obtained from Boeing Commercial Airplane Group, 
P.O. Box 3707, Seattle, Washington 98124-2207. Copies may be 
inspected at the FAA, Transport Airplane Directorate, 1601 Lind 
Avenue, SW., Renton, Washington; or at the Office of the Federal 
Register, 800 North Capitol Street, NW., suite 700, Washington, DC.
    (f) This amendment becomes effective on December 21, 1999.

    Issued in Renton, Washington, on November 4, 1999.
D.L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 99-29471 Filed 11-15-99; 8:45 am]
BILLING CODE 4910-13-P

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