[Federal Register Volume 65, Number 87 (Thursday, May 4, 2000)]
[Rules and Regulations]
[Pages 25833-25838]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-11061]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-NM-94-AD; Amendment 39-11712; AD 2000-09-04]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 767 Series Airplanes 
Equipped with General Electric Model 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 767 series airplanes, that 
currently requires tests, inspections, and adjustments of the thrust 
reverser system. That AD also requires installation of a terminating 
modification, and repetitive follow-on actions. This amendment revises 
certain actions in the existing AD. This amendment is prompted by a 
report indicating that certain instructions referenced in the existing 
AD for accomplishment of the cone brake test of the center drive unit 
are not accurate 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 Boeing Service Bulletin 767-
78A0081, Revision 1, dated October 9, 1997, was previously approved by 
the Director of the Federal Register, as of March 9, 2000 (65 FR 5229, 
February 3, 2000).
    The incorporation by reference of Boeing Service Bulletin 767-78-
0047, Revision 3, dated July 28, 1994; and Boeing Service Bulletin 767-
78-0063, Revision 2, dated April 28, 1994; was previously approved by 
the Director of the Federal Register, as of August 18, 1995 (60 FR 
36976, July 19, 1995).
    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-94-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 24, 2000, the FAA issued AD 2000-
02-20, amendment 39-11538 (65 FR 5229, February 3, 2000), applicable to 
certain Boeing Model 767 series airplanes, to require tests, 
inspections, and adjustments of the thrust reverser system. That action 
also requires installation of a terminating modification, and 
repetitive follow-on actions. That action was prompted by reports 
indicating that several center drive units (CDU's) of the thrust 
reverser system 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 2000-02-20, the FAA has received 
information indicating that the functional test that is described in 
Boeing Service Bulletin 767-78A0081, Revision 1, is not applicable to 
Model 767 series airplanes having a third locking system installed on 
the thrust reversers. For those airplanes, an additional step is 
necessary in order to unlock the electro-mechanical brake, prior to 
accomplishment of the functional test, as described in Appendix 1 
(including Figure 1) of the existing AD. If the test is performed on 
airplanes with the third locking system installed, in accordance with 
the service bulletin, the system will always pass the test, even if the 
cone brake has failed. Paragraph (d) of the existing AD does not 
specifically list which airplanes are required to do the functional 
test of the cone brake of the CDU, in accordance with Boeing Service 
Bulletin 767-78A0081, Revision 1; and which are required to do the test 
in accordance with Appendix 1 (including Figure 1) of the AD. 
Therefore, paragraph (d) of this AD has been revised to separate the 
service information requirements for accurate accomplishment of the 
functional test.
    In addition, 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.

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 2000-02-20 to continue to require tests, inspections, and 
adjustments of the thrust reverser system. The AD also continues to 
require installation of a terminating modification, and repetitive 
follow-on actions. In addition, this AD 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

[[Page 25834]]

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-94-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 Sec. 39.13 is amended by removing amendment 39-11538 (65 
FR 5229, February 3, 2000), and by adding a new airworthiness directive 
(AD), amendment 39-11712, to read as follows:

2000-09-04 Boeing: Amendment 39-11712. Docket 2000-NM-94-AD. 
Supersedes AD 2000-02-20, Amendment 39-11538.

    Applicability: Model 767 series airplanes equipped with General 
Electric Model 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 (i)(1) 
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 Tests, Inspections, and Adjustments

    (a) Within 30 days after August 18, 1995 (the effective date of 
AD 95-13-12 R1, amendment 39-9528), perform tests, inspections, and 
adjustments of the thrust reverser system in accordance with Boeing 
Service Bulletin 767-78-0047, Revision 3, dated July 28, 1994.
    (1) Except as provided by paragraph (a)(2) of this AD, repeat 
all tests and inspections thereafter at intervals not to exceed 
3,000 flight hours until the modification required by paragraph (c) 
of this AD is accomplished.
    (2) Repeat the check of the grounding wire for the Directional 
Pilot Valve (DPV) of the thrust reverser in accordance with the 
service bulletin at intervals not to exceed 1,500 flight hours, and 
whenever maintenance action is taken that would disturb the DPV 
grounding circuit, until the modification required by paragraph (c) 
of this AD is accomplished.

Repair

    (b) If any of the tests and/or inspections required by paragraph 
(a) of this AD cannot be successfully performed, or if those tests 
and/or inspections result in findings that are unacceptable in 
accordance with Boeing Service Bulletin 767-78-0047, Revision 3, 
dated July 28, 1994; accomplish paragraphs (b)(1) and (b)(2) of this 
AD.
    (1) Prior to further flight, deactivate the associated thrust 
reverser in accordance with Section 78-31-1 of Boeing Document 
D630T002, ``Boeing 767 Dispatch Deviation Guide,'' Revision 9, dated 
May 1, 1991; or Revision 10, dated September 1, 1992. After August 
18, 1995, this action shall be accomplished only in accordance with 
Revision 10 of the Boeing document. No more than one reverser on any 
airplane may be deactivated under the provisions of this paragraph.
    (2) Within 10 days after deactivation of any thrust reverser in 
accordance with this paragraph, the thrust reverser must be repaired 
in accordance with Boeing Service Bulletin 767-78-0047, Revision 3, 
dated July 28, 1994. Additionally, the tests and/or inspections 
required by paragraph (a) of this AD must be successfully 
accomplished; once this is accomplished, the thrust reverser must 
then be reactivated.

Modification

    (c) For airplanes having line numbers 1 through 474 inclusive: 
Within 3 years after August 18, 1995, install a third locking system 
on the left- and right-hand engine thrust reversers in accordance 
with Boeing Service Bulletin 767-78-0063, Revision 2, dated April 
28, 1994.

    Note 2: Model 767 series airplanes equipped with General 
Electric Model CF6-80C2 series engines and having line numbers 475 
and subsequent, on which Production Revision Record (PRR) B11481-70 
(which installs a third locking system on the left- and right-hand 
engine thrust reversers) has been incorporated, need NOT be modified 
in accordance with Boeing Service Bulletin 767-78-0063, Revision 2.


    Note 3: Boeing Service Bulletin 767-78-0063, references General 
Electric (GE) Service Bulletin 78-135 as an additional source of 
service information for accomplishment of the third locking system 
on the thrust reversers. However, the Boeing service bulletin does 
not specify the appropriate revision level, and the GE service 
bulletin has a new Lockheed Martin title for the same service 
bulletin: Lockheed Martin Service Bulletin 78-135, Revision 4, dated 
September 30, 1996. The appropriate revision level for the GE 
Service Bulletin is Revision 3, dated August 2, 1994. The GE and 
Lockheed Martin service bulletins are identical, and either may be 
used for accomplishment of the action described previously.


    Note 4: The actions specified in Lockheed Martin Service 
Bulletin 78-1007, Revision 1, dated March 18, 1997; and Lockheed 
Martin Service Bulletin 78-1020, Revision 2, dated March 20, 1997; 
may be accomplished

[[Page 25835]]

simultaneously in conjunction with Boeing Service Bulletin 767-78-
0063 for accomplishment of the installation of the thrust reverser 
bracket and the thrust reverser lock. (Accomplishment of these two 
service bulletins together achieves the same results as Lockheed 
Martin Service Bulletin 78-135, Revision 4, and is acceptable for 
compliance with Boeing Service Bulletin 767-78-0063.)

Repetitive Tests and Checks

    (d) Perform a functional test to detect discrepancies of the 
cone brake of the center drive unit (CDU) on each thrust reverser, 
as specified in paragraph (d)(1) or (d)(2) of this AD, as 
applicable.
    (1) For airplanes on which the modification required by 
paragraph (c) of this AD or a production equivalent has NOT been 
accomplished: Within 650 flight hours after the effective date of 
this AD, perform the test in accordance with Boeing Service Bulletin 
767-78A0081, Revision 1, dated October 9, 1997.
    (2) For airplanes on which the modification required by 
paragraph (c) of this AD or a production equivalent has been 
accomplished: Perform the test in accordance with Appendix 1 
(including Figure 1), sections 1.A.(2), 2.A., 2.C., and 2.D; of this 
AD. Accomplish the test at the time specified in paragraph (d)(2)(i) 
or (d)(2)(ii) of this AD, as applicable.
    (i) For airplanes on which the test required by paragraph (d) of 
AD 95-13-12 R1 HAS been accomplished prior to the effective date of 
this AD: Accomplish the functional test within 1,000 flight hours 
after the most recent test of the CDU cone brake performed in 
accordance with paragraph (d) of AD 95-13-12 R1, or within 650 
flight hours after the effective date of this AD, whichever occurs 
later.
    (ii) For airplanes on which the test required by paragraph (d) 
of AD 95-13-12 R1 has NOT been accomplished prior to the effective 
date of this AD: Accomplish the functional test within 1,000 flight 
hours since the date of manufacture, or within 650 flight hours 
after the effective date of this AD, whichever occurs later.
    (e) Repeat the functional test of the CDU cone brake specified 
in paragraph (d) of this AD at the time specified in paragraph 
(e)(1) or (e)(2) of this AD, as applicable.
    (1) For Model 767 series airplanes, line numbers up to and 
including 474, equipped with thrust reversers that have not been 
modified in accordance with Boeing Service Bulletin 767-78-0063: 
Repeat the functional test of the CDU cone brake thereafter at 
intervals not to exceed 650 flight hours.
    (2) For Model 767 series airplanes, line numbers 475 and 
subsequent; and Model 767 series airplanes equipped with thrust 
reversers that have been modified in accordance with Boeing Service 
Bulletin 767-78-0063, or a production equivalent: Repeat the 
functional test of the CDU cone brake thereafter at intervals not to 
exceed 1,000 flight hours.
    (f) Within 1,000 flight hours after accomplishing the 
modification required by paragraph (c) of this AD or after the 
equivalent modification (Production Revision Record B11481-70) is 
incorporated in production, or within 1,000 flight hours after March 
9, 2000, whichever occurs later: Perform operational checks of the 
electro-mechanical brake in accordance with Appendix 1 (including 
Figure 1); sections 1.A.(1), 2.A., 2.B., and 2.D; of this AD. Repeat 
the operational checks thereafter at intervals not to exceed 1,000 
flight hours.

Repair

    (g) If any functional test or operational check required by 
paragraph (d), (e), or (f) of this AD cannot be successfully 
performed, prior to further flight, repair in accordance with Boeing 
Service Bulletin 767-78A0081, Revision 1, dated October 9, 1997; or 
Appendix 1, section 2.B. and 2.C., of this AD; as applicable; and 
repeat the applicable test or check until successfully accomplished.

Terminating Action

    (h) Accomplishment of the modification required by paragraph (c) 
or installation of an equivalent modification (Production Revision 
Record B11481-70) in production, and accomplishment of the periodic 
functional tests and operational checks required by paragraphs (d), 
(e), and (f) of this AD, constitutes terminating action for the 
tests, inspections, and adjustments required by paragraph (a) of 
this AD.

Alternative Methods of Compliance

    (i)(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 95-13-12, amendment 39-9292, are approved as 
alternative methods of compliance with this AD.

    Note 5: 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

    (j) 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

    (k) Except as provided by paragraphs (b)(1), (d)(2), and (f) of 
this AD, the actions shall be done in accordance with Boeing Service 
Bulletin 767-78-0047, Revision 3, dated July 28, 1994; Boeing 
Service Bulletin 767-78-0063, Revision 2, dated April 28, 1994; and 
Boeing Service Bulletin 767-78A0081, Revision 1, dated October 9, 
1997; as applicable.
    (1) The incorporation by reference of Boeing Service Bulletin 
767-78A0081, Revision 1, dated October 9, 1997, was previously 
approved by the Director of the Federal Register, as of March 9, 
2000 (65 FR 5229, February 3, 2000).
    (2) The incorporation by reference of Boeing Service Bulletin 
767-78-0047, Revision 3, dated July 28, 1994; and Boeing Service 
Bulletin 767-78-0063, Revision 2, dated April 28, 1994; was 
previously approved by the Director of the Federal Register, as of 
August 18, 1995 (60 FR 36976, July 19, 1995).
    (3) 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.
    (l) This amendment becomes effective on May 19, 2000.

Appendix 1.--Thrust Reverser Electro-Mechanical Brake and CDU Cone 
Brake Test

1. General

    A. This procedure contains steps to do two checks:
    (1) A check of the holding torque of the electro-mechanical 
brake.
    (2) A check of the holding torque of the CDU cone brake.
    2. Electro-Mechanical Brake and CDU Cone Brake Torque Check 
(Fig. 1)
    A. Prepare to do the checks:
    (1) Open the fan cowl panels.
    B. Do a check of the torque of the electro-mechanical brake:
    (1) Do a check of the running torque of the thrust reverser 
system:
    (a) Manually extend the thrust reverser six inches and measure 
the running torque.
    (1) Make sure the torque is less than 10 pound-inches.
    (2) Do a check of the electro-mechanical brake holding torque:
    (a) Make sure the thrust reverser translating cowl is extended 
at least one inch.
    (b) Make sure the CDU lock handle is released.
    (c) Pull down on the manual release handle on the electro-
mechanical brake until the handle fully engages the retaining clip.

    Note: This will lock the electro-mechanical brake.

    (d) With the manual drive lockout cover removed from the CDU, 
install a \1/4\-inch extension tool and dial-type torque wrench into 
the drive pad.

    Note: You will need a 24-inch extension to provide adequate 
clearance for the torque wrench.

    (e) Apply 90 pound-inches of torque to the system.
    (1) The electro-mechanical brake system is working correctly if 
the torque is reached before you turn the wrench 450 degrees (1\1/4\ 
turns).
    (2) If the flexshaft turns more than 450 degrees before you 
reach the specified torque, you must replace the long flexshaft 
between the CDU and the upper angle gearbox.
    (3) If you do not get 90 pound-inches of torque, you must 
replace the electro-mechanical brake.
    (f) Release the torque by turning the wrench in the opposite 
direction until you read zero pound-inches.
    (1) If the wrench does not return to within 30 degrees of 
initial starting point, you must

[[Page 25836]]

replace the long flexshaft between the CDU and upper angle gearbox.
    (3) Fully retract the thrust reverser.
    C. Do a check of the CDU cone brake:
    (1) Pull up on the manual release handle to unlock the electro-
mechanical brake.
    (2) 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.

    (3) Return the manual brake release lever to the locked position 
to engage the cone brake.
    (4) Remove the two bolts that hold the lockout plate to the CDU 
and remove the lockout plate.
    (5) 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.

    (6) Turn the torque wrench to try to manually extend the 
translating cowl until you get at lease 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.

    (a) If the torque is less than 15-pound-inches, you must replace 
the CDU.
    D. 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.

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[GRAPHIC] [TIFF OMITTED] TR04MY00.003



[[Page 25838]]


    Issued in Renton, Washington, on April 26, 2000.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 00-11061 Filed 5-3-00; 8:45 am]
BILLING CODE 4910-13-P