[Federal Register Volume 65, Number 138 (Tuesday, July 18, 2000)]
[Rules and Regulations]
[Pages 44432-44434]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-18041]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

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


Airworthiness Directives; Boeing Model 747-400 Series Airplanes 
Equipped with Pratt & Whitney PW4000 Series Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; correction.

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SUMMARY: This document corrects information in an existing 
airworthiness directive (AD) that applies to certain Boeing Model 747-
400 series airplanes. That AD currently requires installation of a 
modification of the thrust reverser control and indication system and 
wiring on each engine; and repetitive functional tests of that 
installation to detect discrepancies, and repair, if necessary. This 
document publishes Appendix 1, which was referenced in, but 
inadvertently omitted from, the existing AD. Appendix 1 describes 
procedures for a functional test to detect discrepancies of the 
additional locking system on each engine thrust reverser. This 
correction is necessary to ensure that operators have the procedures 
necessary to perform the required functional test.

DATES: Effective July 28, 2000.

[[Page 44433]]

    The incorporation by reference of certain publications listed in 
the regulations was approved previously by the Director of the Federal 
Register as of July 28, 2000 (65 FR 39079, June 23, 2000).

FOR FURTHER INFORMATION CONTACT: Larry Reising, Aerospace Engineer, 
Propulsion Branch, ANM-140S, FAA, Transport Airplane Directorate, 
Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056; telephone (425) 227-2683; fax (425) 227-1181.

SUPPLEMENTARY INFORMATION: On June 14, 2000, the Federal Aviation 
Administration (FAA) issued AD 2000-12-21, amendment 39-11799 (65 FR 
39079, June 23, 2000), which applies to certain Boeing Model 747-400 
series airplanes. That AD requires installation of a modification of 
the thrust reverser control and indication system and wiring on each 
engine; and repetitive functional tests of that installation to detect 
discrepancies, and repair, if necessary. That AD was prompted by the 
results of a safety review, which revealed that in-flight deployment of 
a thrust reverser could result in a significant reduction in airplane 
controllability. The actions 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.

Need for the Correction

    Since the issuance of that AD, the FAA discovered that Appendix 1 
was inadvertently omitted from the final version of the AD. Appendix 1 
is referenced in paragraph (b) of the AD as the appropriate source of 
procedures for the functional test to detect discrepancies of the 
additional locking system on each engine thrust reverser. Appendix 1 
was published in the notice of proposed rulemaking (NPRM), which 
preceded the final rule. No comments affecting the procedures described 
in Appendix 1 were received in response to the NPRM.
    The FAA has determined that a correction to AD 2000-12-21 is 
necessary. The correction will add Appendix 1 to the existing AD to 
ensure that operators have the procedures necessary to perform the 
functional test required by paragraph (b) of the AD.

Correction of Publication

    This document adds Appendix 1 and correctly adds the AD as an 
amendment to section 39.13 of the Federal Aviation Regulations (14 CFR 
39.13).
    The AD is reprinted in its entirety for the convenience of affected 
operators. The effective date of the AD remains July 28, 2000.
    Since this action only adds procedures to make it possible for 
operators to accomplish the AD, it has no adverse economic impact and 
imposes no additional burden on any person. Therefore, the FAA has 
determined that notice and public procedures are unnecessary.

List of Subject in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Correction

    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  [Corrected]

    2. Section 39.13 is amended by correctly adding the following 
airworthiness directive (AD):

2000-12-21  Boeing: Amendment 39-11799. Docket 99-NM-66-AD.

    Applicability: Model 747-400 series airplanes equipped with 
Pratt & Whitney PW4000 series engines; certificated in any category.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
modified, altered, or repaired in the area subject to the 
requirements of this AD. For airplanes that have been modified, 
altered, or repaired so that the performance of the requirements of 
this AD is affected, the owner/operator must request approval for an 
alternative method of compliance in accordance with paragraph (d) of 
this AD. The request should include an assessment of the effect of 
the modification, alteration, or repair on the unsafe condition 
addressed by this AD; and, if the unsafe condition has not been 
eliminated, the request should include specific proposed actions to 
address it.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent inadvertent deployment of a thrust reverser during 
flight and consequent reduced controllability of the airplane, 
accomplish the following:

Modifications

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

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

    (2) Prior to or concurrent with the installation required by 
paragraph (a)(1) of this AD, accomplish the requirements of 
paragraphs (a)(2)(i), (a)(2)(ii), and (a)(2)(iii) of this AD:
    (i) Modify the central maintenance computer system hardware and 
software in accordance with Boeing Service Bulletin 747-45-2016, 
Revision 1, dated May 2, 1996.
    (ii) Modify the integrated display system software in accordance 
with Boeing Service Bulletin 747-31-2245, dated June 27, 1996.
    (iii) Install the provisional wiring for the locking system on 
the thrust reversers in accordance with Boeing Service Bulletin 747-
78-2154, Revision 3, dated December 11, 1997.

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

Repetitive Functional Tests

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

Terminating Action Airplanes Having Line Numbers 1067 and Higher

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

[[Page 44434]]

Alternative Methods of Compliance

    (d) An alternative method of compliance or adjustment of the 
compliance time that provides an acceptable level of safety may be 
used if approved by the Manager, Seattle Aircraft Certification 
Office (ACO), FAA, Transport Airplane Directorate. Operators shall 
submit their requests through an appropriate FAA Principal 
Maintenance Inspector, who may add comments and then send it to the 
Manager, Seattle ACO.

    Note 4: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle ACO.

Special Flight Permits

    (e) Special flight permits may be issued in accordance with 
sections 21.197 and 21.199 of the Federal Aviation Regulations (14 
CFR 21.197 and 21.199) to operate the airplane to a location where 
the requirements of this AD can be accomplished.

Incorporation by Reference

    (f) Except as provided by paragraph (b) of this AD, the actions 
shall be done in accordance with Boeing Service Bulletin 747-78-
2155, Revision 2, dated November 5, 1998; Boeing Service Bulletin 
747-45-2016, Revision 1, dated May 2, 1996; Boeing Service Bulletin 
747-31-2245, dated June 27, 1996; or Boeing Service Bulletin 747-78-
2154, Revision 3, dated December 11, 1997; as applicable. This 
incorporation by reference was approved previously by the Director 
of the Federal Register as of July 28, 2000 (65 FR 39079, June 23, 
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.

Effective Date

    (g) The effective date of this amendment remains July 28, 2000.

Appendix 1.--Thrust Reverser Sync-Lock--Adjustment/Test

1. General

    A. There are two sync-locks for each engine thrust reverser. The 
sync-lock is installed on the lower non-locking hydraulic actuator 
of each thrust reverser sleeve.
    B. The Thrust Reverser Sync-Lock Integrity Test has two tasks:
    (1) The first task does a test of the electrical circuit which 
controls the operation of the sync-lock on each thrust reverser 
sleeve.
    (2) The second task does a test of the mechanical function of 
the sync-lock on each thrust reverser sleeve.
    C. The thrust reverser sync-lock is referred to as ``the sync-
lock'' in this procedure.

2. Thrust Reverser Sync-Lock Integrity Test

    A. Equipment--Multi-meter, Simpson 260 or equivalent--
commercially available
    B. Prepare to do the integrity test for the sync-locks
    (1) Supply electrical power
    (2) For the applicable engine, make sure these circuit breakers 
on the Main Power Distribution Panel P6, are closed:

6F12 ENG 1 T/R IND
6E12 ENG 2 T/R IND
6D12 ENG 3 T/R IND
6C12 ENG 4 T/R IND
6F13 ENG 1 T/R CONT
6E13 ENG 2 T/R CONT
6D13 ENG 3 T/R CONT
6C13 ENG 4 T/R CONT
6F11 ENG 1 T/R LOCK CONT
6E11 ENG 2 T/R LOCK CONT
6D11 ENG 3 T/R LOCK CONT
6C11 ENG 4 T/R LOCK CONT

    (3) Open the fan cowl panels for the applicable engine.
    C. Do the electrical integrity test for the sync-locks.
    (1) Do these steps, for the applicable engine, to make sure 
there are no ``hot'' short circuits in the electrical system which 
can accidentally supply power to the sync-locks:
    (a) Remove the electrical connector, D20194, from the sync-lock, 
V170, on the left sleeve of the thrust reverser.
    (b) Remove the electrical connector, D20196, from the sync-lock, 
V171, on the right sleeve of the thrust reverser.
    (c) Use a multi-meter on the plug end of the applicable 
electrical connector to make sure that these conditions are correct:


D20194 PIN 1              D20194 PIN 2             -3 TO +1 VDC AND
                                                    CONTINUITY (LESS
                                                    THAN 5 OHMS)
D20196 PIN 1              D20196 PIN 2             -3 TO +1 VDC AND
                                                    CONTINUITY (LESS
                                                    THAN 5 OHMS)
 

    (d) If you find the correct conditions, do the mechanical 
integrity test for the sync-locks.
    (e) If you did not find these conditions to be correct, you must 
do these steps:
    (1) Make a careful visual inspection of all the electrical wires 
and connectors between the sync-lock and its power circuit.
    (2) Repair all the unserviceable electrical wire and connectors 
that you find.
    (3) Use the multi-meter again to make sure there are no ``hot'' 
short circuits in the electrical system which can accidentally 
supply power to the sync-locks.
    D. Do the mechanical integrity test for the sync-locks.
    (1) Supply hydraulic power.

    WARNING: MAKE SURE ALL PERSONS AND EQUIPMENT ARE CLEAR OF THE 
AREA BEHIND EACH THRUST REVERSER. IF YOU DO NOT OBEY THIS 
INSTRUCTION, INJURIES TO PERSONS OR DAMAGE TO EQUIPMENT CAN OCCUR IF 
THE SYNC-LOCKS DO NOT OPERATE CORRECTLY AND THE THRUST REVERSER 
EXTENDS.

    (2) Move the applicable reverser thrust lever aft to try to 
extend the thrust reverser with hydraulic power.

    Note: If the thrust reverser sleeves do not extend, the sync-
locks are serviceable. If the thrust reverser sleeves extend, the 
applicable sync-lock did not operate correctly.

    (3) Replace the sync-lock(s) on the thrust reverser sleeve(s) 
that did extend when you moved the reverse thrust levers. Repeat 
steps 2.D.(1) and 2.D.(2) to verify that functional sync-locks are 
installed.
    (4) Move the applicable thrust reverser lever forward to the 
stow position.
    (5) Install the electrical connector, D20194, on the sync-lock, 
V170 on the left sleeve of the thrust reverser.
    (6) Install the electrical connector, D20196, on the sync-lock, 
V171, on the right sleeve of the thrust reverser.

    WARNING: MAKE SURE ALL PERSONS AND EQUIPMENT ARE CLEAR OF THE 
AREA BEHIND EACH THRUST REVERSER. IF YOU DO NOT OBEY THIS 
INSTRUCTION, INJURIES TO PERSONS OR DAMAGE TO EQUIPMENT CAN OCCUR 
WHEN THE THRUST REVERSERS ARE EXTENDED.

    (7) Move the applicable thrust reverser aft to try to extend the 
thrust reverser with hydraulic power.

    Note: If the thrust reverser sleeves extended, the sync-locks 
are serviceable. If the thrust reverser sleeves did not extend, the 
applicable sync-lock is not serviceable.

    (8) Replace the sync-lock(s) on the thrust reverser sleeve that 
did not extend when you moved the reverse thrust levers. Repeat 
steps 2.D.(4) through 2.D.(7) to verify that functional sync-locks 
are installed.
    (9) Repeat steps 2.A. through 2.D. for all other engine 
positions.
    E. Put the airplane back to its usual condition.
    (1) Move the reverse thrust levers forward to fully retract the 
thrust reversers on the applicable engine.
    (2) Remove the hydraulic power if it is not necessary.
    (3) Remove the electrical power if it is not necessary.
    (4) Close the fan cowl panels.

    Issued in Renton, Washington, on July 11, 2000.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 00-18041 Filed 7-17-00; 8:45 am]
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