[Federal Register Volume 59, Number 205 (Tuesday, October 25, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-24451]


[[Page Unknown]]

[Federal Register: October 25, 1994]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 94-NM-37-AD; Amendment 39-9040; AD 94-20-11]

 

Airworthiness Directives; Boeing Model 747-400 Series Airplanes 
Equipped With Pratt & Whitney PW4000 Series Engines

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 747-400 series airplanes, that 
requires replacement of the thrust reverser flow restrictor devices 
with one-way (check) valve restrictors. This amendment is prompted by 
reports of actuator piston seal leakage found during actuator overhaul 
on certain Model 747-400 series airplanes. The actions specified by 
this AD are intended to prevent possible deployment of a thrust 
reverser in flight and subsequent reduced controllability of the 
airplane.

DATES: Effective November 25, 1994.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of November 25, 1994.

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: Jon Regimbal, Aerospace Engineer, 
Propulsion Branch, ANM-140S, FAA, Transport Airplane Directorate, 
Seattle Aircraft Certification Office, 1601 Lind Avenue SW., Renton, 
Washington 98055-4056; telephone (206) 227-2687; fax (206) 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 747-400 
series airplanes was published in the Federal Register on April 22, 
1994 (59 FR 19151). That action proposed to require replacement of the 
thrust reverser flow restrictor devices with one-way (check) valve 
restrictors.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.
    The Air Transport Association (ATA) of America, on behalf of one of 
its members, requests that the proposed rule be revised to cite the 
latest revision of Boeing Alert Service Bulletin 747-78A2128. The FAA 
concurs. Since the issuance of the proposed rule, the FAA has reviewed 
and approved Revision 1, dated May 26, 1994, of the Boeing alert 
service bulletin. Revision 1 corrects certain discrepancies contained 
in the original issue of the alert service bulletin. The FAA has 
revised paragraph (a) of the final rule to reflect the latest revision 
to the alert service bulletin as an additional source of service 
information.
    After careful review of the available data, including the comments 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule with the change previously 
described. The FAA has determined that this change will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.
    There are approximately 94 Model 747-400 series airplanes of the 
affected design in the worldwide fleet. The FAA estimates that 32 
airplanes of U.S. registry will be affected by this AD, that it will 
take approximately 24 work hours per airplane to accomplish the 
required actions, and that the average labor rate is $55 per work hour. 
Required parts will be supplied by the manufacturer at no cost to 
operators. Based on these figures, the total cost impact of the AD on 
U.S. operators is estimated to be $42,240, or $1,320 per airplane.
    The total cost impact figure discussed above is 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.
    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. App. 1354(a), 1421 and 1423; 49 U.S.C. 
106(g); and 14 CFR 11.89.


Sec. 39.13  [Amended]

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

94-20-11 Boeing: Amendment 39-9040. Docket 94-NM-37-AD.

    Applicability: Model 747-400 series airplanes up to and 
including line position 1022, equipped with Pratt & Whitney PW4000 
series engines, certificated in any category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent possible deployment of a thrust reverser in flight 
and subsequent reduced controllability of the airplane, accomplish 
the following:
    (a) Within 18 months after the effective date of this AD, 
replace the thrust reverser flow restrictor devices with one-way 
(check) valve restrictors in accordance with Boeing Alert Service 
Bulletin 747-78A2128, dated March 10, 1994; or Revision 1, dated May 
26, 1994.
    (b) 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: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle ACO.

    (c) 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.
    (d) The replacement shall be done in accordance with Boeing 
Alert Service Bulletin 747-78A2128, dated March 10, 1994; or Boeing 
Alert Service Bulletin 747-78A2128, Revision 1, dated May 26, 1994. 
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.
    (e) This amendment becomes effective on November 25, 1994.

    Issued in Renton, Washington, on September 28, 1994.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 94-24451 Filed 10-24-94; 8:45 am]
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