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[Federal Register Volume 59, Number 156 (Monday, August 15, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 94-19481]

[[Page Unknown]]

[Federal Register: August 15, 1994]

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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 92-NM-237-AD; Amendment 39-8998; AD 94-17-03]

 

Airworthiness Directives; Boeing Model 767 Series Airplanes 
Equipped With Rolls-Royce RB211-524 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 767 series airplanes, that requires 
inspections, adjustments, and functional checks of the thrust reverser 
system; installation of a terminating modification; and repetitive 
operational checks of the gearbox locks and the air motor brake 
following accomplishment of the modification. This amendment is 
prompted by the identification of a modification that ensures that the 
level of safety inherent in the original type design of the thrust 
reverser system is further enhanced. The actions specified by this AD 
are intended to prevent possible discrepancies that exist in the 
current thrust reverser control system, which could result in an 
inadvertent deployment of a thrust reverser during flight.

DATES: Effective September 14, 1994.
    The incorporation by reference of certain publications, as listed 
in the regulations, is approved by the Director of the Federal Register 
as of September 14, 1994.
    The incorporation by reference of Boeing Service Bulletin 767-78-
0048, dated August 15, 1991, listed in the regulations was approved 
previously by the Director of the Federal Register as of October 15, 
1991 (56 FR 51638, October 15, 1991).

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: Lanny Pinkstaff, Aerospace Engineer, 
Propulsion Branch, ANM-140S, FAA, Transport Airplane Directorate, 
Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056; telephone (206) 227-2684; fax (206) 227-1181.

SUPPLEMENTARY INFORMATION:
    A proposal to amend part 39 of the Federal Aviation Regulations (14 
CFR part 39) to include an airworthiness directive (AD) that is 
applicable to certain Boeing Model 767 series airplanes was published 
in the Federal Register on August 6, 1993 (58 FR 42032). That action 
proposed to supersede AD 91-22-02, Amendment 39-8062 (56 FR 51638, 
October 15, 1991), to require inspections, adjustments, and functional 
checks of the thrust reverser system on Model 767 series airplanes 
equipped with Rolls-Royce RB211-524 or General Electric CF6-80C2 series 
engines. That action also proposed to require installation of a 
terminating modification and repetitive operational checks of the 
gearbox locks and the air motor brake following accomplishment of that 
modification on Model 767 series airplanes equipped with Rolls- Royce 
RB211-524 series engines.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.
    One commenter supports the proposed rule.
    The Air Transport Association (ATA) of America, on behalf of one of 
its members, requests that two immediately adopted rules be created 
from this proposed rule: one for airplanes equipped with Rolls-Royce 
RB211-524 series engines, and the other for the airplanes equipped with 
General Electric CF6-80C2 series engines. If either of the two rules 
should be revised in the future, the superseded rule would only apply 
to the operators actually affected, and operators having airplanes with 
the other engine type would not be required to change their AD 
compliance records.
    The FAA concurs that two separate AD's should be created from the 
proposal. Therefore, this final rule has been revised to require those 
actions specified in the proposal for Model 767 series airplanes 
equipped with Rolls-Royce RB211-524 series engines only. Paragraph (a) 
of this final rule has been revised to specify that accomplishment of 
the actions required by that paragraph terminates the actions required 
by paragraph (a) of AD 91-22-02. Subsequently, the FAA may consider 
superseding AD 91-22-02 to remove the requirements for Model 767 series 
airplanes equipped with Rolls-Royce RB211-524 series engines from that 
AD, to specify that those requirements are contained in this AD, and to 
require accomplishment of a terminating modification for Model 767 
series airplanes equipped with General Electric CF6-80C2 series engines 
(once that modification becomes available).
    The economic impact information, below, has also been revised to 
specify the costs associated with accomplishment of the actions 
required by this AD for those airplanes equipped with Rolls-Royce 
RB211-524 series engines only.
    Boeing requests that specific references to page numbers and 
revision dates of the Boeing 767 Airplane Maintenance Manual (AMM) be 
eliminated from the AD. Boeing recommends that the proposed AD specify 
only the ATA Chapter-Section-Subject, pageblock, and task title. Boeing 
explains that the AMM's are customized for each operator to reflect all 
of the equipment in that operator's fleet. Therefore, the number of 
pages for any given procedure is variable, depending on the number of 
different equipment configurations documented in an operator's AMM.
    Boeing also indicates that AMM procedures are revised periodically 
for non-technical reasons. Boeing adds that changes to the structure of 
the procedures are necessary to accommodate an upgrade of the 
publishing system that is currently under way, which, in addition to 
repagination, will necessitate the issuance of revised AMM pages.
    Boeing states that the effect of specifying AMM page numbers and 
revision dates in the AD is that operators may be unable to use the 
procedure contained in the AMM to perform certain tests required by the 
AD. Each operator would be required to maintain an obsolete version of 
the procedure, or to request FAA approval of an alternative method of 
compliance with the AD that would allow the use of the current version 
of the AMM.
    The FAA concurs partially. In light of the information submitted by 
the commenter, the FAA agrees that specific AMM page numbers and dates 
should not be specified in the final rule. However, the FAA does not 
agree with the commenter's recommendation that the final rule specify 
the ATA Chapter-Section-Subject, pageblock, and task title. The FAA's 
objective in proposing periodic operational checks of the gearbox locks 
and the air motor brake is to ensure the integrity of the locking 
function. Since the issuance of the proposal and receipt of Boeing's 
comments to the proposal, Boeing has submitted to the FAA separate 
procedures for accomplishment of the operational check of the integrity 
of the gearbox locks and the air motor brake. For clarification 
purposes, the requirements of paragraph (d) of the proposal have been 
separated into two paragraphs [(c) and (d)] of the final rule. The AMM 
references specified in paragraph (c) of the proposal have been removed 
from the final rule. Paragraph (d) of the final rule specifies that the 
operational checks are required to be accomplished in accordance with 
the procedures that appear in Appendix 1 (including Figure 1) of this 
AD.
    Since the issuance of the proposal, the FAA has reviewed and 
approved Boeing Service Bulletin 767-78-0059, Revision 3, dated January 
20, 1994, which adds a note in several locations to specify that 
whenever a changed or disconnected connector is connected, an 
inspection of the disconnected electrical connectors to detect bent or 
pushed-back pins should be performed. This inspection is necessary 
simply to verify the correct installation of the connectors; the FAA 
does not consider that this inspection will impose an additional burden 
on any operator. Additionally, the revised service bulletin references 
the latest version of a particular wire kit to show changes in wiring 
information. Paragraph (c) of the final rule has been revised to 
reflect the latest revision of the service bulletin as an additional 
source of service information.
    It should be noted that Revisions 2 and 3 of Boeing Service 
Bulletin 767-78-0059 reference Rolls-Royce Service Bulletins RB.211-71-
9608, RB.211-71-9600, and RB.211-71-9601, and Eldec Service Bulletin 8-
651-32-01 as additional sources of service information for 
accomplishment of the locking gearbox installation. However, the Boeing 
service bulletins do not specify the appropriate revision levels for 
those Rolls-Royce and Eldec service bulletins. Therefore, the FAA has 
added ``NOTE 1'' to paragraph (c) of this AD to specify that the intent 
of that paragraph is that the appropriate revision levels for the 
Rolls-Royce and Eldec service bulletins to be used in conjunction with 
Boeing Service Bulletin 767-78-0059 are as follows: Rolls-Royce Service 
Bulletin RB.211-71-9608, Revision 1, dated October 2, 1992; Rolls-Royce 
Service Bulletin RB.211-71-9600, Revision 4, dated February 11, 1994; 
Rolls-Royce Service Bulletin RB.211-71-9601, Revision 1, dated October 
2, 1992; and Eldec Service Bulletin 8-651-32-01, dated January 31, 
1992.
    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.
    Currently, there are no Model 767 series airplanes equipped with 
Rolls-Royce RB211-524 series engines on the U.S. Register. However, 
should an affected airplane be imported and placed on the U.S. Register 
in the future, it will require approximately 22 work hours to 
accomplish the inspections, adjustments, and functional checks, 754 
work hours to accomplish the modification, and 1 work hour to 
accomplish the operational checks of the modification, at an average 
labor rate of $55 per work hour. Required parts will be supplied by the 
manufacturer at no cost to operators. Based on these figures, the total 
cost impact for the required actions will be $42,735 per airplane.
    The regulations adopted herein will not have substantial direct 
effects on the States, on the relationship between the national 
government and the States, or on the distribution of power and 
responsibilities among the various levels of government. Therefore, in 
accordance with Executive Order 12612, it is determined that this final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this action (1) is 
not a ``significant regulatory action'' under Executive Order 12866; 
(2) is not a ``significant rule'' under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979); and (3) will not have a 
significant economic impact, positive or negative, on a substantial 
number of small entities under the criteria of the Regulatory 
Flexibility Act. A final evaluation has been prepared for this action 
and it is contained in the Rules Docket. A copy of it may be obtained 
from the Rules Docket at the location provided under the caption 
ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety. Adoption of the Amendment.
    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends part 39 of 
the Federal Aviation Regulations (14 CFR part 39) as follows:

PART 39--AIRWORTHINESS DIRECTIVES -

    1. The authority citation for part 39 continues to read as follows:

    Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 
106(g); and 14 CFR 11.89.

Sec. 39.13  [Amended] -

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

94-17-03 BOEING: Amendment 39-8998. Docket 92-NM-237-AD.

     -Applicability: Model 767 series airplanes equipped with Rolls-
Royce RB211-524 series engines, certificated in any category. -
    Compliance: Required as indicated, unless accomplished 
previously. -
    To ensure the integrity of the fail safe features of the thrust 
reverser system, accomplish the following: -
    (a) Within 30 days after October 15, 1991 (the effective date of 
AD 91-22-02, Amendment 39-8062), perform the inspections, 
adjustments, and functional checks described in Boeing Service 
Bulletin 767-78-0048, dated August 15, 1991, or Revision 1, dated 
March 26, 1992. Perform those actions in accordance with procedures 
described in the service bulletin. After the effective date of this 
AD, those actions shall be accomplished only in accordance with 
Revision 1 of the service bulletin. Accomplishment of the actions 
required by this paragraph terminates the actions required by 
paragraph (a) of AD 91-22-02, amendment 39-8062. -
    (1) Except as provided by paragraph (a)(2) of this AD, repeat 
all inspections and functional checks in accordance with the service 
bulletin at intervals not to exceed 3,000 flight hours. -
    (2) Repeat the functional check of the grounding wire for the 
thrust reverser Selector Sequence Valve (SSV) 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 SSV 
grounding circuit. -
    (b) If any of the inspections and/or functional checks required 
by paragraph (a) of this AD cannot be successfully performed, or if 
those inspections and/or functional checks result in findings that 
are unacceptable in accordance with Boeing Service Bulletin 767-78-
0048, dated August 15, 1991, or Revision 1, dated March 26, 1992, 
accomplish paragraphs (b)(1) and (b)(2) of this AD. After the 
effective date of this AD, the actions required by paragraph (b)(2) 
of this AD shall be accomplished only in accordance with Boeing 
Service Bulletin 767-78-0048, Revision 1, dated March 26, 1992. -
    (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 11, 
dated March 15, 1993. No more than one thrust 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 767-78-0048, dated August 
15, 1991, or Revision 1, dated March 26, 1992. Additionally, the 
inspections and/or functional checks required by paragraph (a) of 
this AD must be successfully accomplished; once this is 
accomplished, the thrust reverser must then be reactivated. -
    (c) Within 3 years after the effective date of this AD, install 
a second locking gearbox system on the left- and right-hand engine 
thrust reversers, in accordance with Boeing Service Bulletin 767-78-
0059, Revision 2, dated June 10, 1993; or Revision 3, dated January 
20, 1994.

    -Note 1: Revisions 2 and 3 of Boeing Service Bulletin 767-78-
0059 reference Rolls-Royce Service Bulletins RB.211-71-9608, RB.211-
71-9600, and RB.211-71-9601, and Eldec Service Bulletin 8-651-32-01 
as additional sources of service information for accomplishment of 
the locking gearbox installation. However, the Boeing service 
bulletins do not specify the appropriate revision levels for those 
Rolls-Royce and Eldec service bulletins. The appropriate revision 
levels for the Rolls-Royce and Eldec service bulletins to be used in 
conjunction with Boeing Service Bulletin 767-78-0059 are as follows: 
Rolls-Royce Service Bulletin RB.211-71-9608, Revision 1, dated 
October 2, 1992; Rolls-Royce Service Bulletin RB.211-71-9600, 
Revision 4, dated February 11, 1994; Rolls-Royce Service Bulletin 
RB.211-71-9601, Revision 1, dated October 2, 1992; and Eldec Service 
Bulletin 8-651-32-01, dated January 31, 1992.

    -(d) Within 3,000 flight hours after accomplishing the 
modification required by paragraph (c) of this AD, or within 1,000 
flight hours after the effective date of this AD, whichever occurs 
later; and thereafter at intervals not to exceed 3,000 flight hours; 
perform operational checks of the number 2 and number 3 gearbox 
locks and of the air motor brake in accordance with Appendix 1 
(including Figure 1) of this AD. -
    (e) Accomplishment of the modification and periodic operational 
checks required by paragraphs (c) and (d) of this AD constitutes 
terminating action for the inspections, adjustments, and functional 
checks required by paragraph (a) of this AD. -
    (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.

     -(g) Special flight permits may be issued in accordance with 
sections 21.197 and 21.199 of the Federal Aviation Regulations (FAR) 
(14 CFR 21.197 and 21.199) to operate the airplane to a location 
where the requirements of this AD can be accomplished. -
    (h) Certain actions shall be done in accordance with Boeing 
Service Bulletin 767-78-0048, Revision 1, dated March 26, 1992; and 
Boeing Service Bulletin 767-78-0059, Revision 2, dated June 10, 
1993, or Boeing Service Bulletin 767-78-0059, Revision 3, dated 
January 20, 1994. The incorporation by reference of these documents 
was approved by the Director of the Federal Register in accordance 
with 5 U.S.C. 552(a) and 1 CFR part 51. Certain other actions shall 
be done in accordance with Boeing Service Bulletin 767-78-0048, 
dated August 15, 1991. The incorporation by reference of that 
document was approved previously by the Director of the Federal 
Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51 as of 
October 15, 1991 (56 FR 51638). 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 September 14, 1994.

Appendix 1

1. Gearbox Lock and Air Motor Brake Test

A. General

    (1) 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 of 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 system. 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 extends 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 gearbox locks:

    Note: The steps that follow are for the No. 3 gearbox. Then do 
these steps again for the No. 2 gearbox.

    (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 the 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 POUNDS-
INCHES (3.4 NEWTON-METERS) TO MANUAL CYCLE AND LOCKOUT 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 a 
\1/4\ of a 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. It 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 a 
\1/4\ of a 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 tools 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-M

TR15AU94.000

BILLING CODE 4910-13-C
    Issued in Renton, Washington, on August 4, 1994.
James V. Devany,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 94-19481 Filed 8-12-94; 8:45 am]
BILLING CODE 4910-13-U
```