[Federal Register Volume 65, Number 122 (Friday, June 23, 2000)]
[Rules and Regulations]
[Pages 39079-39081]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-15545]



[[Page 39079]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-66-AD; Amendment 39-11799; AD 2000-12-21]
RIN 2120-AA64


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. The AD 
requires installation of a modification of the thrust reverser control 
and indication system and wiring on each engine; and repetitive 
functional tests of that installation to detect discrepancies, and 
repair, if necessary. This amendment is prompted by the results of a 
safety review, which revealed that in-flight deployment of a thrust 
reverser could result in a significant reduction in airplane 
controllability. The actions specified by this AD are intended to 
ensure the integrity of the fail-safe features of the thrust reverser 
system by preventing possible failure modes, which could result in 
inadvertent deployment of a thrust reverser during flight, and 
consequent reduced controllability of the airplane.

DATES: Effective July 28, 2000.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of July 28, 2000.

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: Larry Reising, Aerospace Engineer, 
Propulsion Branch, ANM-140S, FAA, Transport Airplane Directorate, 
Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056; telephone (425) 227-2683; 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 747-400 
series airplanes was published in the Federal Register on December 28, 
1999 (64 FR 72579). That action proposed to require installation of a 
modification of the thrust reverser control and indication system and 
wiring on each engine; and repetitive functional tests of that 
installation to detect discrepancies, and repair, if necessary.

Comments

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.

Support for the Proposed Rule

    One commenter states that it has no objection to the proposed rule 
and does not anticipate any adverse impact due to the proposed rule.

Request to Reference Previous Revisions of Service Bulletins

    Two commenters request that the FAA revise the proposed rule to 
reference Boeing Service Bulletin 747-78-2155, Revision 1, dated 
January 30, 1997, as an acceptable source of service information for 
accomplishment of the actions specified in paragraph (a)(1) of the 
proposed rule. [The proposed rule referenced Revision 2 of Boeing 
Service Bulletin 747-78-2155, dated November 5, 1998, as the 
appropriate source of service information for the actions specified in 
paragraph (a)(1).] One of the commenters also requests that the FAA 
revise paragraph (a)(2)(iii) of the proposed rule to reference Boeing 
Service Bulletin 747-78-2154, Revision 1, dated November 2, 1995, and 
Revision 2, dated October 31, 1996, as acceptable sources of service 
information. [The proposed rule referenced Revision 3 of Boeing Service 
Bulletin 747-78-2154, dated December 11, 1997, as the appropriate 
source of service information for the actions specified in paragraph 
(a)(2)(iii).] One of the commenters, an operator, states that it has 
already modified its Model 747-400 series airplanes using Boeing 
Service Bulletin 747-78-2155, Revision 1. The other commenter notes 
that the earlier issues of the service bulletins are similar to the 
revisions referenced in the proposed rule, which only made corrections 
of typographical errors and clarifications of illustrations.
    The FAA concurs with the commenters' requests. The FAA has reviewed 
and approved Boeing Service Bulletins 747-78-2155, Revision 1, and 747-
78-2154, Revisions 1 and 2, and finds that they are substantially 
similar to the later revisions of the service bulletins referenced in 
the proposed rule. Accordingly, two new notes (Note 2 and Note 3) have 
been added to this final rule to give credit for accomplishment of the 
actions in paragraphs (a)(1) and (a)(2)(iii) of this AD prior to the 
effective date of this AD in accordance with the earlier revisions of 
the service bulletins described previously.

Request To Specify Terminating Action

    One commenter requests that the proposed rule be revised to specify 
that, for airplanes having line numbers 1067 and higher on which the 
intent of Boeing Service Bulletin 747-78-2155 was accomplished during 
production, this AD is terminating action for AD 94-15-05, amendment 
39-8976 (59 FR 37655, July 25, 1994). The commenter states that this is 
not clear in the proposed rule.
    Because paragraph (a) of this AD does not apply to airplanes having 
line numbers 1067 and higher, the FAA infers that the commenter is 
requesting that paragraph (b) of the proposed rule be revised to state 
that accomplishment of the functional test in that paragraph 
constitutes terminating action for the actions required by AD 94-15-05. 
The FAA concurs with the commenter's request. Paragraph (a) of AD 94-
15-05 requires various inspections and functional tests of the thrust 
reverser control and indication system, and correction of any 
discrepancy found, on Boeing Model 747-400 series airplanes powered by 
Pratt & Whitney PW4000 series engines. For airplanes having line 
numbers 1067 and higher on which the intent of Boeing Service Bulletin 
747-78-2155 was accomplished during production, accomplishment of the 
repetitive functional tests required by paragraph (b) of this AD 
constitutes terminating action for the repetitive inspections and 
functional tests required by paragraph (a) of AD 94-15-05. Therefore, a 
new paragraph (c) has been added to this AD to state this, and all 
subsequent paragraphs have been relettered accordingly.

Explanation of Additional Change to Proposed Rule

    Paragraph (b) of the proposed rule contains an incorrect reference. 
That paragraph specifies that any discrepancy detected during the 
functional test must be corrected in accordance with procedures 
described in the Boeing 747 Airplane Maintenance

[[Page 39080]]

Manual. The correct source of service information for the 
accomplishment of corrective actions is the Boeing 747-400 Airplane 
Maintenance Manual. Paragraph (b) of this final rule has been revised 
accordingly.

Conclusion

    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 changes previously 
described. The FAA has determined that these changes will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.

Cost Impact

    There are approximately 177 Model 747-400 series airplanes of the 
affected design in the worldwide fleet. The FAA estimates that 53 
airplanes of U.S. registry will be affected by this AD.
    For airplanes identified in Boeing Service Bulletin 747-78-2155, 
Revision 2 (45 airplanes), it takes approximately 510 work hours per 
airplane to accomplish the required installation, at an average labor 
rate of $60 per work hour. Required parts will be provided by the 
manufacturer at no cost to the operators. Based on these figures, the 
cost impact of the installation required by this AD on U.S. operators 
is estimated to be $1,377,000, or $30,600 per airplane.
    For all airplanes (53 airplanes) it will take approximately 2 work 
hours per airplane to accomplish the required functional test, at an 
average labor rate of $60 per work hour. Based on these figures, the 
cost impact of the functional test required by this AD on U.S. 
operators is estimated to be $6,360, or $120 per airplane, per test 
cycle.
    The cost impact figures discussed below refer to actions in other 
service bulletins for the airplanes identified in Boeing Service 
Bulletin 747-78-2155, Revision 2 (affects 45 U.S.-registered 
airplanes), that must be accomplished prior to or concurrent with the 
installation specified in Boeing Service Bulletin 747-78-2155, Revision 
2.
    It will take approximately 3 work hours per airplane to accomplish 
the central maintenance computer system modification, at an average 
labor rate of $60 per work hour. Required parts will be provided by the 
manufacturer at no cost to the operators. Based on these figures, the 
cost impact of this modification is estimated to be $8,100, or $180 per 
airplane.
    It will take approximately 2 work hours per airplane to accomplish 
the changes to the integrated display system, at an average labor rate 
of $60 per work hour. Required parts will be provided by the 
manufacturer at no cost to the operators. Based on these figures, the 
cost impact of this modification is estimated to be $5,400, or $120 per 
airplane.
    It will take approximately 346 work hours per airplane to 
accomplish wiring provisions for the thrust reverser sync locks, at an 
average labor rate of $60 per work hour. Required parts will be 
provided by the manufacturer at no cost to the operators. Based on 
these figures, the cost impact of this modification is estimated to be 
$934,200, or $20,760 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 a substantial direct 
effect 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, it 
is determined that this final rule does not have federalism 
implications under Executive Order 13132.
    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:

2000-12-21  Boeing: Amendment 39-11799. Docket 99-NM-66-AD.
    Applicability: Model 747-400 series airplanes equipped with 
Pratt & Whitney PW4000 series engines; 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 (d) 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 inadvertent deployment of a thrust reverser during 
flight and consequent reduced controllability of the airplane, 
accomplish the following:

Modifications

    (a) For airplanes identified in Boeing Service Bulletin 747-78-
2155, Revision 2, dated November 5, 1998: Accomplish the 
requirements of paragraphs (a)(1) and (a)(2) of this AD at the times 
specified in those paragraphs. Accomplishment of these actions 
constitutes terminating action for the inspections and tests 
required by paragraph (a) of AD 94-15-05, amendment 39-8976.
    (1) Within 36 months after the effective date of this AD: 
Install an additional locking system on each engine thrust reverser 
in accordance with the Accomplishment Instructions of Boeing Service 
Bulletin 747-78-2155, Revision 2, dated November 5, 1998.

    Note 2: Installations accomplished prior to the effective date 
of this AD in accordance with Boeing Service Bulletin 747-78-2155, 
Revision 1, dated January 30, 1997, are considered acceptable for 
compliance with paragraph (a)(1) of this AD.

    (2) Prior to or concurrent with the installation required by 
paragraph (a)(1) of this AD, accomplish the requirements of 
paragraphs (a)(2)(i), (a)(2)(ii), and (a)(2)(iii) of this AD:
    (i) Modify the central maintenance computer system hardware and 
software in accordance with Boeing Service Bulletin 747-45-2016, 
Revision 1, dated May 2, 1996.

[[Page 39081]]

    (ii) Modify the integrated display system software in accordance 
with Boeing Service Bulletin 747-31-2245, dated June 27, 1996.
    (iii) Install the provisional wiring for the locking system on 
the thrust reversers in accordance with Boeing Service Bulletin 747-
78-2154, Revision 3, dated December 11, 1997.

    Note 3: Installations accomplished prior to the effective date 
of this AD in accordance with Boeing Service Bulletin 747-78-2154, 
Revision 1, dated November 2, 1995, and Revision 2, dated October 
31, 1996, are considered acceptable for compliance with paragraph 
(a)(2)(iii) of this AD.

Repetitive Functional Tests

    (b) Within 4,000 hours time-in-service after accomplishment of 
paragraph (a) of this AD, or production equivalent; or within 1,000 
hours time-in-service after the effective date of this AD, whichever 
occurs later: Perform a functional test to detect discrepancies of 
the additional locking system on each engine thrust reverser, in 
accordance with Appendix 1 of this AD. Prior to further flight, 
correct any discrepancy detected and repeat the functional test of 
that repair, in accordance with the procedures described in the 
Boeing 747-400 Airplane Maintenance Manual. Repeat the functional 
test thereafter at intervals not to exceed 4,000 hours time-in-
service.

Terminating Action: Airplanes Having Line Numbers 1067 and Higher

    (c) For airplanes having line numbers 1067 and higher on which 
the intent of Boeing Service Bulletin 747-78-2155, Revision 2, dated 
November 5, 1998, was accomplished during production: Accomplishment 
of the repetitive functional tests required by paragraph (b) of this 
AD constitutes terminating action for the repetitive inspections and 
functional tests required by paragraph (a) of AD 94-15-05, amendment 
39-8976.

Alternative Methods of Compliance

    (d) 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 4: 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

    (e) Special flight permits may be issued in accordance with 
sections 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

    (f) Except as provided by paragraph (b) of this AD, the actions 
shall be done in accordance with Boeing Service Bulletin 747-78-
2155, Revision 2, dated November 5, 1998; Boeing Service Bulletin 
747-45-2016, Revision 1, dated May 2, 1996; Boeing Service Bulletin 
747-31-2245, dated June 27, 1996; or Boeing Service Bulletin 747-78-
2154, Revision 3, dated December 11, 1997; 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.

Effective Date

    (g) This amendment becomes effective on July 28, 2000.

    Issued in Renton, Washington, on June 14, 2000.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 00-15545 Filed 6-22-00; 8:45 am]
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