[Federal Register Volume 65, Number 87 (Thursday, May 4, 2000)]
[Rules and Regulations]
[Pages 25829-25833]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-11060]



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Rules and Regulations
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Federal Register / Vol. 65, No. 87 / Thursday, May 4, 2000 / Rules 
and Regulations

[[Page 25829]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-NM-93-AD; Amendment 39-11711; AD 2000-09-03]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747-400 Series Airplanes 
Equipped With General Electric CF6-80C2 Series Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment supersedes an existing airworthiness directive 
(AD), applicable to certain Boeing Model 747-400 series airplanes, that 
currently requires various inspections and functional tests to detect 
discrepancies of the thrust reverser control and indication system, and 
correction of any discrepancy found. This amendment adds an appendix 
and revises certain actions in the existing AD. This amendment is 
prompted by a report indicating that completion of the cone brake test 
of the center drive unit is ineffective for certain airplanes. The 
actions specified in this AD are intended to ensure the integrity of 
the fail safe features of the thrust reverser system by preventing 
possible failure modes in the thrust reverser control system that can 
result in inadvertent deployment of a thrust reverser during flight.

DATES: Effective May 19, 2000.
    The incorporation by reference of certain publications, as listed 
in the regulations, was previously approved by the Director of the 
Federal Register as of March 13, 2000 (65 FR 5742, February 7, 2000).
    Comments for inclusion in the Rules Docket must be received on or 
before July 3, 2000.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2000-NM-93-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056.
    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 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.

FOR FURTHER INFORMATION CONTACT: Holly Thorson, Aerospace Engineer, 
Propulsion Branch, ANM-140S, FAA, Transport Airplane Directorate, 
Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056; telephone (425) 227-1357; fax (425) 227-1181.

SUPPLEMENTARY INFORMATION: On January 28, 2000, the FAA issued AD 2000-
02-33, amendment 39-11551 (65 FR 5742, February 7, 2000), applicable to 
certain Boeing Model 747-400 series airplanes, to require various 
inspections and functional tests to detect discrepancies of the thrust 
reverser control and indication system, and correction of any 
discrepancy found. That action was prompted by reports indicating that 
several center drive units (CDU) were returned to the manufacturer of 
the CDU's because of low holding torque of the CDU cone brake. The 
actions required by that AD are intended to ensure the integrity of the 
fail safe features of the thrust reverser system by preventing possible 
failure modes in the thrust reverser control system that can result in 
inadvertent deployment of a thrust reverser during flight.

Actions Since Issuance of Previous Rule

    Since the issuance of AD 2000-02-33, the FAA has received 
information indicating the following:
    <bullet> Completion of the functional test of the CDU cone brake as 
referenced in the existing AD is ineffective for Model 747-400 series 
airplanes having a third locking system installed on the thrust 
reversers. The test for those airplanes requires an additional step to 
unlock the electro-mechanical brake prior to accomplishment of the 
functional test of the cone brake of the center drive unit. This step 
was omitted from the functional test described in the service bulletins 
and referenced in paragraph (a) of the existing AD. Therefore, Appendix 
1 (including Figure 1) has been added to this AD to provide accurate 
instructions for airplanes that have a third locking system installed. 
Paragraph (a) of this AD has been revised to reference Appendix 1 
(including Figure 1) as the appropriate source of service information 
for those airplanes.
    <bullet> The grace period of 650 flight hours to accomplish the 
functional test of the cone brake of the CDU is expected to expire for 
most airplanes by May or June 2000. For airplanes that have been 
modified to incorporate the third locking system, this would allow 
accomplishment of an invalid test with potentially misleading results. 
The valid functional test as described in Appendix 1 (including Figure 
1) of this AD imposes no additional burden.
    <bullet> The previously approved alternative methods of compliance 
(AMOC) as referenced in paragraph (d)(2) of the existing AD should not 
have been included in the final rule. The notice of proposed rulemaking 
was issued as a supersedure, but the final rule was issued as a 
separate rulemaking action that addressed only those airplanes equipped 
with General Electric CF6-80C2 series engines; therefore, the AMOC's 
previously approved in accordance with AD 94-15-05, amendment 39-8976 
(59 FR 37655, July 25, 1994), and specified in paragraph (d)(2) of the 
existing AD, are not applicable. Paragraph (d)(2) of the existing AD 
has been revised accordingly.
    <bullet> Paragraph (a) of the existing AD states, ``Within 1,000 
hours time-in-service after the most recent test of the CDU cone brake 
performed in accordance with paragraph (b)(1) of AD 94-15-05; or within 
650 hours time-in-service after the effective date of this AD, 
whichever occurs first * * *'' The manufacturer has submitted 
documentation showing similar requirements are contained in paragraph 
(a) of AD 2000-02-20, amendment 39-11551, which is applicable to Model 
767 series airplanes, and which gives the

[[Page 25830]]

operator a longer compliance time. In that AD, the grace period for the 
compliance time reads, ``* * * or within 650 hours time-in-service 
after the effective date of this AD, whichever occurs later * * *'' 
Therefore, in light of the information received, the FAA has revised 
paragraph (a) of this AD accordingly.

Explanation of Requirements of Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other airplanes of this same type design, this AD 
supersedes AD 2000-02-33 to continue to require various inspections and 
functional tests to detect discrepancies of the thrust reverser control 
and indication system, and correction of any discrepancy found. This AD 
also adds an appendix and revises certain actions in the existing AD.

Determination of Rule's Effective Date

    Since a situation exists that requires the immediate adoption of 
this regulation, it is found that notice and opportunity for prior 
public comment hereon are impracticable, and that good cause exists for 
making this amendment effective in less than 30 days.

Comments Invited

    Although this action is in the form of a final rule that involves 
requirements affecting flight safety and, thus, was not preceded by 
notice and an opportunity for public comment, comments are invited on 
this rule. Interested persons are invited to comment on this rule by 
submitting such written data, views, or arguments as they may desire.
    Communications shall identify the Rules Docket number and be 
submitted in triplicate to the address specified under the caption 
ADDRESSES. All communications received on or before the closing date 
for comments will be considered, and this rule may be amended in light 
of the comments received. Factual information that supports the 
commenter's ideas and suggestions is extremely helpful in evaluating 
the effectiveness of the AD action and determining whether additional 
rulemaking action would be needed.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the rule that might 
suggest a need to modify the rule. All comments submitted will be 
available, both before and after the closing date for comments, in the 
Rules Docket for examination by interested persons. A report that 
summarizes each FAA-public contact concerned with the substance of this 
AD will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this rule must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 2000-NM-93-AD.'' The postcard will be date stamped and 
returned to the commenter.

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.
    The FAA has determined that this regulation is an emergency 
regulation that must be issued immediately to correct an unsafe 
condition in aircraft, and that it is not a ``significant regulatory 
action'' under Executive Order 12866. It has been determined further 
that this action involves an emergency regulation under DOT Regulatory 
Policies and Procedures (44 FR 11034, February 26, 1979). If it is 
determined that this emergency regulation otherwise would be 
significant under DOT Regulatory Policies and Procedures, a final 
regulatory evaluation will be prepared and placed in the Rules Docket.
    A copy of it, if filed, 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 removing amendment 39-11551 (65 FR 
5742, February 7, 2000), and by adding a new airworthiness directive 
(AD), amendment 39-11711, to read as follows:

2000-09-03 Boeing: Amendment 39-11711. Docket 2000-NM-93-AD. 
Supersedes AD 2000-02-33, Amendment 39-11551.

    Applicability: Model 747-400 series airplanes equipped with 
General Electric (GE) CF6-80C2 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 ensure the integrity of the fail safe features of the thrust 
reverser system by preventing possible failure modes in the thrust 
reverser control system that can result in inadvertent deployment of 
a thrust reverser during flight, accomplish the following:

Repetitive Functional Tests

    (a) Within 1,000 hours time-in-service after the most recent 
test of the center drive unit (CDU) cone brake as specified in 
paragraph (b)(1) of AD 94-15-05, amendment 39-8976; or within 650 
hours time-in-service after the effective date of this AD; whichever 
occurs later: Perform a functional test to detect discrepancies of 
the CDU cone brake on each thrust reverser as specified in paragraph 
(a)(1) or (a)(2) of this AD, as applicable.
    (1) For Model 747-400 series airplanes equipped with thrust 
reversers that have NOT been modified in accordance with Boeing 
Service Bulletin 747-78-2151 or a production equivalent: Perform the 
test in accordance with Boeing Service Bulletin 747-78A2166, 
Revision 1, dated October 9, 1997; or the applicable section of 
paragraph III.A. of the Accomplishment Instructions of Boeing 
Service Bulletin 747-78A2113, Revision 2, dated June 8, 1995, or 
Revision 3, dated September 11, 1997. Repeat the test thereafter at 
intervals not to exceed 650 hours time-in-service.
    (2) For Model 747-400 series airplanes equipped with thrust 
reversers that HAVE been modified in accordance with Boeing Service 
Bulletin 747-78-2151 or a production equivalent: Perform the test in 
accordance with Appendix 1 (including Figure 1) of this AD. Repeat 
the test thereafter at intervals not to exceed 1,000 hours time-in-
service.

    Note 2: Accomplishment of the CDU cone brake test during 
production in accordance with Production Revision Record (PRR) 
80452-102 prior to the effective date of this AD is considered 
acceptable for compliance

[[Page 25831]]

with the initial test required by paragraph (a) of this AD.


    Note 3: Model 747-400 series airplanes, line numbers 1061 and 
subsequent, equipped with GE CF6-80C2 engines, had a third locking 
system installed during production in accordance with Production 
Revision Record (PRR) 80452-102, and were not modified in accordance 
with Boeing Service Bulletin 747-78-2151 (which is a retrofit action 
for airplanes having line numbers 700 through 1060 inclusive).

Terminating Action

    (b) Accomplishment of the functional test of the CDU cone brake, 
as specified in paragraph (a) of this AD, constitutes terminating 
action for the repetitive tests of the CDU cone brake required by 
paragraph (b)(1) of AD 94-15-05.

Corrective Action

    (c) If any functional test required by paragraph (a) of this AD 
cannot be successfully performed as specified in the referenced 
service bulletin, or if any discrepancy is detected during any 
functional test required by paragraph (a) of this AD, accomplish 
either paragraph (c)(1) or (c)(2) of this AD.
    (1) Prior to further flight, repair in accordance with Boeing 
Service Bulletin 747-78A2166, Revision 1, dated October 9, 1997; or 
Boeing Service Bulletin 747-78A2113, Revision 2, dated June 8, 1995, 
or Revision 3, dated September 11, 1997.
    Or,
    (2) The airplane may be operated in accordance with the 
provisions and limitations specified in the operator's FAA-approved 
MEL, provided that no more than one thrust reverser on the airplane 
is inoperative.

Alternative Methods of Compliance

    (d)(1) 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.
    (2) Alternative methods of compliance approved previously in 
accordance with AD 2000-02-33, Amendment 39-11551, are considered to 
be approved as alternative methods of compliance with this AD.

    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 paragraphs (a)(2) and (c)(2) of this 
AD, the actions shall be done in accordance with Boeing Service 
Bulletin 747-78A2166, Revision 1, dated October 9, 1997; Boeing 
Service Bulletin 747-78A2113, Revision 2, dated June 8, 1995; and 
Boeing Service Bulletin 747-78A2113, Revision 3, dated September 11, 
1997. This incorporation by reference was previously approved by the 
Director of the Federal Register as of March 13, 2000 (65 FR 5742, 
February 7, 2000). 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.
    (g) This amendment becomes effective on May 19, 2000.

Appendix 1.--Thrust Reverser CDU Cone Brake Test

    1. This procedure contains steps to do a check of the holding 
torque of the CDU cone brake.
    2. CDU cone brake check (Figure 1):
    A. Prepare to do the check:
    (1) Open the fan cowl panels.
    (2) Pull up on the manual release handle to unlock the electro-
mechanical brake.
    (3) Pull the manual brake release lever on the CDU to release 
the cone brake.

    Note: This will release the pre-load tension that may occur 
during a stow cycle.

    (4) Return the manual brake release lever to the locked position 
to engage the cone brake.
    (5) Remove the two bolts that hold the lockout plate to the CDU 
and remove the lockout plate.
    (6) Install a \1/4\-inch drive and a dial-type torque wrench 
into the CDU drive pad.

    CAUTION: DO NOT USE MORE THAN 100 POUND-INCHES OF TORQUE WHEN 
YOU DO THIS CHECK. EXCESSIVE TORQUE WILL DAMAGE THE CDU.

    (7) Turn the torque wrench to try to manually extend the 
translating cowl until you get at least 15 pound-inches.

    Note: The cone brake prevents movement in the extend direction 
only. If you try to measure the holding torque in the retract 
direction, you will get a false reading.

    (8) If the torque is less than 15 pound-inches, you must replace 
the CDU.
    (9) Reinstall the lockout plate.
    B. Return the airplane to its usual condition:
    (1) Fully retract the thrust reverser (unless already 
accomplished).
    (2) Pull down on the manual release handle on the electro-
mechanical brake until the handle fully engages the retaining clip 
(unless already accomplished).

    Note: This will lock the electro-mechanical brake.

    (3) Close the fan cowl panels.

[[Page 25832]]

[GRAPHIC] [TIFF OMITTED] TR04MY00.002



[[Page 25833]]


    Issued in Renton, Washington, on April 26, 2000.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 00-11060 Filed 5-3-00; 8:45 am]
BILLING CODE 4910-13-P