00-374. Airworthiness Directives; Boeing Model 747 Series Airplanes  

  • [Federal Register Volume 65, Number 5 (Friday, January 7, 2000)]
    [Rules and Regulations]
    [Pages 1051-1055]
    From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
    [FR Doc No: 00-374]
    
    
    
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    Federal Register / Vol. 65, No. 5 / Friday, January 7, 2000 / Rules 
    and Regulations
    
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    DEPARTMENT OF TRANSPORTATION
    
    Federal Aviation Administration
    
    14 CFR Part 39
    
    [Docket No. 99-NM-361-AD; Amendment 39-11502; AD 2000-01-05]
    RIN 2120-AA64
    
    
    Airworthiness Directives; Boeing Model 747 Series Airplanes
    
    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 series airplanes. That AD 
    currently requires repetitive inspections and tests of the thrust 
    reverser control and indication system on each engine, and corrective 
    actions, if necessary; installation of a terminating modification; and 
    repetitive operational checks of that installation, 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 significant reduction in airplane controllability. 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, which could result in inadvertent deployment of 
    a thrust reverser during flight, and consequent reduced controllability 
    of the airplane. This action identifies certain repetitive operational 
    checks that were inadvertently omitted from the existing AD, and 
    revises certain procedures for accomplishment of the operational checks 
    and certain follow-on corrective actions.
    
    DATES: Effective January 24, 2000.
        The incorporation by reference of certain publications as listed in 
    the regulations was approved previously by the Director of the Federal 
    Register as of September 15, 1999 (64 FR 47365, August 31, 1999).
        Comments for inclusion in the Rules Docket must be received on or 
    before March 7, 2000.
    
    ADDRESSES: Submit comments in triplicate to the Federal Aviation 
    Administration (FAA), Transport Airplane Directorate, ANM-114, 
    Attention: Rules Docket No. 99-NM-361-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: Ed Hormel, Aerospace Engineer, 
    Propulsion Branch, ANM-140S, FAA, Transport Airplane Directorate, 
    Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, 
    Washington 98055-4056; telephone (206) 227-2681; fax (206) 227-1181.
    
    SUPPLEMENTARY INFORMATION: On August 19, 1999, the FAA issued AD 99-18-
    03, amendment 39-11269 (64 FR 47365, August 31, 1999), applicable to 
    certain Boeing Model 747 series airplanes. That AD requires repetitive 
    inspections and tests of the thrust reverser control and indication 
    system on each engine, and corrective actions, if necessary; 
    installation of a terminating modification; and repetitive operational 
    checks of that installation, and repair, if necessary. That AD was 
    prompted by the results of a safety review, which revealed that in-
    flight deployment of a thrust reverser could result in significant 
    reduction in airplane controllability. 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, which 
    could result in inadvertent deployment of a thrust reverser during 
    flight, and consequent reduced controllability of the airplane.
    
    Actions Since Issuance of Previous Rule
    
        Since the issuance of AD 99-18-03, the FAA finds that it 
    inadvertently omitted reference to the accomplishment of repetitive 
    operational checks; however, the Summary and Explanation of 
    Requirements of the Rule sections both specified accomplishment of the 
    repetitive operational checks. The FAA's intent in paragraph (d) of 
    that AD was to require operators to perform repetitive operational 
    checks at intervals not to exceed 3,000 flight hours following 
    accomplishment of the initial operational check. Paragraph (d) of this 
    AD has been revised accordingly.
        The FAA also has determined that the procedures in the Airplane 
    Maintenance Manual (AMM) are inadequately defined to allow for 
    accomplishment of the operational checks; therefore, the procedures are 
    included in an appendix to this AD. Accordingly, this action revises 
    paragraphs (d) and (e) of that AD to remove all references to the AMM 
    for accomplishment of the operational checks, and replace those 
    references with references to Appendix 1 (including Figure 1) of this 
    AD, which describes the Gearbox Lock and Air Motor Brake Test 
    procedures required for accomplishment of the operational checks.
        In addition, all references to the procedures specified in the 
    Master Minimum Equipment List and the Dispatch Deviation Guide in 
    paragraphs (b) and (e) of the existing AD have been removed because the 
    FAA is unable to determine that an airplane is safe for operation if 
    the thrust reverser functional tests are not successfully passed, or if 
    the tests are unable to be performed. These procedures are retracted by 
    the FAA because failure of the functional test might indicate that a 
    fault or faults are present, which could lead to an uncommanded 
    deployment of a thrust reverser during flight.
    
    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 99-18-03 to continue to require repetitive inspections 
    and tests of the thrust reverser control and indication system on each 
    engine, and corrective actions, if necessary; installation of a 
    terminating modification; and repetitive operational checks of that 
    installation, and repair, if necessary. The actions are required to be 
    accomplished in
    
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    accordance with the service bulletins described previously, except as 
    discussed below.
        Repetitive operational checks to detect discrepancies of the 
    gearbox locks and the air motor brake are required to be accomplished 
    in accordance with the procedure included in Appendix 1 (including 
    Figure 1) of this AD. Correction of any discrepancy detected is 
    required to be accomplished in accordance with the procedures described 
    in the Boeing 747 Airplane Maintenance Manual.
    
    Cost Impact
    
        None of the Model 747 series airplanes affected by this action are 
    on the U.S. Register. All airplanes included in the applicability of 
    this rule currently are operated by non-U.S. operators under foreign 
    registry; therefore, they are not directly affected by this AD action. 
    However, the FAA considers that this rule is necessary to ensure that 
    the unsafe condition is addressed in the event that any of these 
    subject airplanes are imported and placed on the U.S. Register in the 
    future.
        Should an affected airplane be imported and placed on the U.S. 
    Register in the future:
        It would require approximately 24 work hours (6 work hours per 
    engine) to accomplish the required inspections and tests, at an average 
    labor rate of $60 per work hour. Based on these figures, the cost 
    impact of the inspections and tests required by this AD would be 
    approximately $1,440 per airplane, per inspection/test cycle.
        It would require approximately 392 work hours to accomplish the 
    required installation of provisional wiring, at an average labor rate 
    of $60 per work hour. Required parts would cost approximately $22,298 
    per airplane. Based on these figures, the cost impact of this 
    modification required by this AD would be approximately $45,818 per 
    airplane.
        It would require approximately 306 work hours to accomplish the 
    required installation of the locking gearbox, at an average labor rate 
    of $60 per work hour. Required parts would 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 would be 
    approximately $18,360 per airplane.
        It would require approximately 2 work hours to accomplish the 
    required operational check, at an average labor rate of $60 per work 
    hour. Based on these figures, the cost impact of the operational check 
    required by this AD would be approximately $120 per airplane, per 
    check.
    
    Determination of Rule's Effective Date
    
        Since this AD action does not affect any airplane that is currently 
    on the U.S. register, it has no adverse economic impact and imposes no 
    additional burden on any person. Therefore, prior notice and public 
    procedures hereon are unnecessary and the amendment may be made 
    effective in less than 30 days after publication in the Federal 
    Register.
    
    Comments Invited
    
        Although this action is in the form of a final rule and was not 
    preceded by notice and 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 99-NM-361-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.
        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 removing amendment 39-11269 (64 FR 
    47365, August 31, 1999), and by adding a new airworthiness directive 
    (AD), amendment 39-11502, to read as follows:
    
    2000-01-05 Boeing: Amendment 39-11502. Docket 99-NM-361-AD. 
    Supersedes AD 99-18-03, Amendment 39-11269.
    
        Applicability: Model 747-100B, -200, -300, and SP series 
    airplanes, equipped with Rolls Royce RB211-524B2, C2, and D4 
    engines; certificated in any category, as listed in the following 
    service bulletins:
         Boeing Alert Service Bulletin 747-78A2148, dated June 
    1, 1995;
         Boeing Service Bulletin 747-78A2148, Revision 1, dated 
    July 20, 1995;
         Boeing Service Bulletin 747-78-2136, dated May 11, 
    1995; and
         Boeing Service Bulletin 747-78-2156, dated October 31, 
    1996.
    
        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 (f) of 
    this AD. The request should include an assessment of the
    
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    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:
    
    Restatement of Requirements of AD 
    99-18-03
    
    Repetitive Inspections and Tests
    
        (a) Within 90 days after September 15, 1999 (the effective date 
    of AD 99-18-03, amendment 39-11269): Perform the applicable 
    inspections and tests of the thrust reverser control and indication 
    system on each engine, in accordance with Part III.A. through III.G. 
    of the Accomplishment Instructions of Boeing Alert Service Bulletin 
    747-78A2148, dated June 1, 1995, or Boeing Service Bulletin 747-
    78A2148, Revision 1, dated July 20, 1995. Repeat the applicable 
    inspections and tests thereafter at intervals not to exceed 18 
    months, until accomplishment of paragraph (c) of this AD.
    
    Corrective Actions
    
        (b) If any inspection or test required by paragraph (a) of this 
    AD cannot be successfully performed as specified in the service 
    bulletin, or if any discrepancy is detected during any inspection or 
    test, prior to further flight, repair in accordance with Boeing 
    Alert Service Bulletin 747-78A2148, dated June 1, 1995, or Boeing 
    Service Bulletin 747-78A2148, Revision 1, dated July 20, 1995. 
    Additionally, prior to further flight, any failed inspection or test 
    required by paragraph (a) of this AD must be repeated and 
    successfully accomplished.
    
    Modification
    
        (c) Within 36 months after September 15, 1999: Install an 
    additional locking system on the thrust reversers in accordance with 
    the Accomplishment Instructions of Boeing Service Bulletin 747-78-
    2156, dated October 31, 1996. Prior to or concurrent with 
    accomplishment of Boeing Service Bulletin 747-78-2156, dated October 
    31, 1996: Accomplish Boeing Service Bulletin 747-78-2136, dated May 
    11, 1995; and Rolls-Royce Service Bulletins RB.211-71-B545, Revision 
    2, dated August 8, 1997, RB.211-71-B551, Revision 1, dated March 20, 
    1998, and RB.211-78-B552, dated June 21, 1996.
        Accomplishment of these actions constitutes terminating action 
    for the repetitive inspections and tests required by paragraph (a) 
    of this AD.
    
    Operational Checks
    
        (d) Within 3,000 flight hours after accomplishing the 
    modification required by paragraph (c) of this AD, or within 1,000 
    flight hours after September 15, 1999, whichever occurs later: 
    Perform operational checks of the number 2 and number 3 gearbox 
    locks and of the air motor brake, in accordance with the procedures 
    described in Appendix 1 (including Figure 1) of this AD. Repeat the 
    operational checks thereafter at intervals not to exceed 3,000 
    flight hours.
    
    Corrective Actions
    
        (e) If any operational check required by paragraph (d) of this 
    AD cannot be successfully performed as specified in the procedures 
    described in Appendix 1 (including Figure 1) of this AD, or, if any 
    discrepancy is detected during any operational check, prior to 
    further flight, repair in accordance with the procedures specified 
    in the Boeing 747 Airplane Maintenance Manual. Additionally, prior 
    to further flight, any failed operational check required by 
    paragraph (d) of this AD must be repeated and successfully 
    accomplished. Continue to repeat the operational checks thereafter 
    at intervals not to exceed 3,000 flight hours.
    
    Alternative Methods of Compliance
    
        (f) 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 2: 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
    
        (g) 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
    
        (h) Except as provided by paragraphs (d) and (e) of this AD, the 
    actions shall be done in accordance with the applicable service 
    bulletins:
         Boeing Service Bulletin 747-78-2136, dated May 11, 
    1995;
         Boeing Alert Service Bulletin 747-78A2148, dated June 
    1, 1995;
         Boeing Service Bulletin 747-78A2148, Revision 1, dated 
    July 20, 1995;
         Boeing Service Bulletin 747-78-2156, dated October 31, 
    1996;
         Rolls-Royce Service Bulletin RB.211-78-B552, dated June 
    21, 1996;
         Rolls-Royce Service Bulletin RB.211-71-B545, Revision 
    2, dated August 8, 1997; or
         Rolls-Royce Service Bulletin RB.211-71-B551, Revision 
    1, dated March 20, 1998.
    
    This incorporation by reference was approved previously by the 
    Director of the Federal Register as of September 15, 1999 (64 FR 
    47365, August 31, 1999). 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.
        (i) This amendment becomes effective on January 24, 2000.
    
    Appendix 1--
    
    Gearbox Lock and Air Motor Brake Test
    
    A. General
    
        To do the test of the gearbox locks and air motor brake, you 
    must do the steps that follow:
        (a) Do the deactivation procedure of the thrust reverser system.
        (b) Do the test of the air motor brake.
        (c) Do the test of the gearbox locks.
        (d) Do the activation procedure of the thrust reverser system.
    
    B. Equipment
    
        (1) CP30784--INA Access Platform, Rolls-Royce
        (2) CP30769--Protection Pads, Rolls-Royce
        (3) CP30785--Access Stools, Rolls-Royce
        (4) UT1293/1--Load Tool, Rolls-Royce (2 required)
    
    C. Procedure (Fig. 1)
    
    Warning: Do the Deactivation Procedure of the Thrust Reverser 
    System, Which Must Include the Installation of Lock Bars (or 
    Blockers), to Prevent the Accidental operation of the Thrust 
    Reverser. The Accidental Operation of the Thrust Reverser Could 
    Cause Injury to Persons and Damage to Equipment.
    
        (1) Do the deactivation procedure of the thrust reverser in the 
    forward thrust position for ground maintenance.
        (2) Use a 0.25-inch (6.4-mm) square drive to turn the manual 
    lock release screw to release the No. 2 and No. 3 gearbox locks.
    
        Note: It is not always easy to turn the manual lock release 
    screws. This is because of a preload in the systems. To release the 
    preload, lightly turn the manual cycle and lockout shafts in the 
    stow direction.
    
        (a) Make sure the lock indicators are extended at gearboxes No. 
    2 and No. 3.
        (3) Do a test of the air motor brake:
        (a) If You Use the Load Tools;
        Try to move the translating cowl in the extend direction as 
    follows:
        (1) Remove the lock bars that you installed in the deactivation 
    procedure.
        (2) Install the load tools through the cutouts and into the No. 
    2 and No. 3 gearboxes.
        (3) Attach the torque wrenches to the load tools.
        (4) Try to move the translating cowl in the extend direction.
        (b) If You Do Not Use the Load Tools;
        Try to move the translating cowl in the extend direction as 
    follows:
        (1) Remove the lock bars that you installed in the deactivation 
    procedure.
        (2) Put the 0.25-inch (6.4-mm) square drive extensions into the 
    manual cycle and lockout shaft at the No. 2 and No. 3 gearboxes.
        (a) Attach the standard drive tools.
        (3) Try to move the translating cowl in the extend direction.
        (c) If the translating cowl moves, replace the air motor and 
    shutoff valve.
        (4) Do a test of the gear box locks:
    
        Note: The steps that follow are for the No. 3 gearbox. Then, do 
    these steps again for the No. 2 gearbox.
    
    
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        (a) Install the lock bars in the manual cycle and lockout shafts 
    at the No. 2 and No. 3 gearboxes.
        (b) Install the INA access platform in the exhaust mixer duct.
        (c) Install the protection pads and the access stools.
        (d) Release the air motor brake:
        (1) Open the air motor access and pressure relief panel.
        (2) Pull the air motor brake release handle forward and turn it 
    counterclockwise to lock the handle in its position.
        (e) Turn the manual lock release screw clockwise to engage the 
    No. 3 gearbox lock.
        (1) Make sure that the lock indicator is retracted (under the 
    surface) at gearbox No. 3.
        (f) Make sure No. 2 gearbox lock is released.
        (1) Make sure the lock indicator is extended at gearbox No. 2.
        (g) If You Use the Load Tools;
        Do a check of the lock dogs as follows:
        (1) Remove the lock bars from the No. 2 and No. 3 gearboxes.
        (2) Install the load tool through the cutout and into the No. 3 
    gearbox.
        (3) Attach the torque wrench to the load tool.
    
    Caution: Do Not Apply a Torque Load of More Than 30 Pound-Inches 
    (3.4 Newton-Meters) to the Manual Cycle and Lock Out Shaft. A Larger 
    Torque Load Can Cause Damage to the Mechanism.
    
        (4) Apply a torque counterclockwise through the manual wind 
    position of the No. 3 gearbox.
        (a) If the translating cowl does not move, the lock bar touched 
    one of the two lock dogs.
        (b) If the translating cowl moved, lock the thrust reverser 
    until the No. 3 gearbox is replaced.
        (5) Turn the manual lock release screw counterclockwise to 
    release the gearbox lock.
        (a) Make sure that the indication rod comes out of the No. 3 
    gearbox.
        (6) Turn the manual cycle and lockout shaft counterclockwise \1/
    4\ turn.
        (7) Turn the manual lock release screw clockwise to engage the 
    No. 3 gearbox lock.
        (a) Make sure that the indication rod is fully retracted (under 
    the surface).
    
    Caution: Do Not Apply a Torque Load of More Than 30 Pound-Inches 
    (3.4 Newton-Meters) to the Manual Cycle and Lockout Shaft. A Greater 
    Torque Load Can Cause Damage to the Mechanism.
    
        (8) Apply a torque counterclockwise through the manual wind 
    position of the No. 3 gearbox.
        (a) If the manual cycle and lockout shaft can not be turned more 
    than approximately \1/4\ turn, the second lock dog is serviceable.
        (b) If the manual cycle and lockout shaft can be turned more 
    than approximately \1/4\ turn, the second lock dog is unserviceable. 
    Lock the thrust reverser until the No. 3 gearbox is replaced.
    
        Note: The two lock dogs are found \1/2\ turn apart when you use 
    the manual cycle and lockout shaft. If necessary, do the check again 
    to make sure that the lock dogs are serviceable.
    
        (9) Do the procedure given above for the No. 2 gearbox lock.
        (h) If You Do Not Use the Load Tools;
        Do a check of the lock dogs as follows:
        (1) Remove the lock bars from the No. 2 and No. 3 gearboxes.
        (2) Put the 0.25-inch (6.4-mm) square drive extensions into the 
    manual cycle and lockout shaft at the No. 2 and No. 3 gearboxes.
        (a) Attach the standard drive tools.
    
    Caution: Do Not Apply a Torque Load of More Than 30 Pound-Inches 
    (3.4 Newton-Meters) to the Manual Cycle and Lockout Shaft. A Larger 
    Torque Load Can Cause Damage to the Mechanism.
    
        (3) Apply a torque counterclockwise through the manual wind 
    position of the No. 3 gearbox.
        (a) If the translating cowl does not move, the lock bar touched 
    one of the two lock dogs.
        (b) If the translating cowl moved, lock the thrust reverser 
    until the No. 3 gearbox is replaced.
        (4) Turn the manual lock release screw counterclockwise to 
    release the gearbox lock.
        (a) Make sure that the indication rod comes out of the No. 3 
    gearbox.
        (5) Turn the manual cycle and lockout shaft counterclockwise \1/
    4\ turn.
        (6) Turn the manual lock release screw clockwise to engage the 
    No. 3 gearbox lock.
        (a) Make sure that the indication rod is fully retracted (under 
    the surface).
    
    Caution: Do Not Apply a Torque Load of More Than 30 Pound-Inches 
    (3.4 Newton-Meters) to the Manual Cycle and Lockout Shaft. A Greater 
    Torque Load Can Cause Damage to the Mechanism.
    
        (7) Apply a torque counterclockwise through the manual wind 
    position of the No. 3 gearbox.
        (a) If the manual cycle and lockout shaft can not be turned more 
    than approximately \1/4\ turn, the second lock dog is serviceable.
        (b) If the manual cycle and lockout shaft can be turned more 
    than approximately \1/4\ turn, the second lock dog is unserviceable. 
    Lock the thrust reverser until the No. 3 gearbox is replaced.
    
        Note: The two lock dogs are found \1/2\ turn apart when you use 
    the manual cycle and lockout shaft. If necessary, do the check again 
    to make sure that the lock dogs are serviceable.
    
        (8) Do the procedure given above for the No. 2 gearbox lock.
        (5) Install the lock bars in the manual cycle and lockout shafts 
    at the No. 2 and No. 3 gearboxes.
        (6) Apply the air motor manual brake:
        (a) Turn the air motor brake release handle clockwise and then 
    release.
        (b) Close the air motor access and pressure relief panel.
        (7) Make sure the No. 2 and No. 3 gearbox locks are released.
        (a) Make sure the lock indicator rods are extended at the No. 2 
    and No. 3 gearboxes.
        (8) If You Use the Load Tools;
        Try to move the translating cowl in the extend direction as 
    follows:
        (a) Remove the lock bars from the No. 2 and No. 3 gearboxes.
        (b) Install the load tools through the cutouts and into the No. 
    2 and No. 3 gearboxes.
        (c) Attach the torque wrenches to the load tools.
        (d) Try to move the translating cowl in the extend direction.
        (9) If You Do Not Use the Load Tools;
        Try to move the translating cowl in the extend direction as 
    follows:
        (a) Remove the lock bars from the No. 2 and No. 3 gearboxes.
        (b) Put the 0.25-inch (6.4-mm) square drive extensions into the 
    manual cycle and lockout shaft at the No. 2 and No. 3 gearboxes.
        (1) Attach the standard drive tools.
        (c) Try to move the translating cowl in the extend direction.
        (10) If the translating cowl moves, do the full test again.
        (a) If the translating sleeve moves again, lock the thrust 
    reverser until you can replace the two locking gearboxes and the air 
    motor and shutoff valve.
        (11) Remove the access stools and protection pads.
        (12) Remove the INA access platform from the exhaust mixer duct.
        (13) Do the activation procedure of the thrust reverser system.
        (14) Do the functional test of the thrust reverser system.
    
    BILLING CODE 4910-13-U
    
    [[Page 1055]]
    
    [GRAPHIC] [TIFF OMITTED] TR07JA00.000
    
    
    
        Issued in Renton, Washington, on January 3, 2000.
    Vi L. Lipski,
    Acting Manager, Transport Airplane Directorate, Aircraft Certification 
    Service.
    [FR Doc. 00-374 Filed 1-6-00; 8:45 am]
    BILLING CODE 4910-13-C
    
    
    

Document Information

Effective Date:
1/24/2000
Published:
01/07/2000
Department:
Federal Aviation Administration
Entry Type:
Rule
Action:
Final rule; request for comments.
Document Number:
00-374
Dates:
Effective January 24, 2000.
Pages:
1051-1055 (5 pages)
Docket Numbers:
Docket No. 99-NM-361-AD, Amendment 39-11502, AD 2000-01-05
RINs:
2120-AA64: Airworthiness Directives
RIN Links:
https://www.federalregister.gov/regulations/2120-AA64/airworthiness-directives
PDF File:
00-374.pdf
CFR: (1)
14 CFR 39.13