Airworthiness Directives; Boeing Model 747 Series Airplanes Equipped With Pratt & Whitney JT9D-70 Series Engines

[Federal Register Volume 65, Number 103 (Friday, May 26, 2000)]
[Rules and Regulations]
[Pages 34048-34054]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-12812]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-65-AD; Amendment 39-11741; AD 2000-10-17]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747 Series Airplanes 
Equipped With Pratt & Whitney JT9D-70 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 747 series airplanes, that requires 
inspections, tests, and certain modifications of the thrust reverser 
control and indication system and wiring on each engine, and corrective 
action, if necessary. This amendment also requires installation of a 
terminating modification, and repetitive functional tests of that 
installation to detect discrepancies, 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 by 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.

DATES: Effective June 30, 2000.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of June 30, 2000.

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: 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: 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 747 series 
airplanes was published in the Federal Register on February 4, 2000 (65 
FR 5459). That action proposed to require inspections, tests, and 
certain modifications of the thrust reverser control and indication 
system and wiring on each engine, and corrective action, if necessary. 
That action also proposed to require installation of a terminating 
modification, and repetitive functional tests of that installation to 
detect discrepancies, and repair, if necessary.

Comments

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. No comments were submitted in response 
to the proposal or the FAA's determination of the cost to the public.

Conclusion

    The FAA has determined that air safety and the public interest 
require the adoption of the rule as proposed.

Cost Impact

    There are approximately 7 Model 747 series airplanes of the 
affected design in the worldwide fleet. The FAA estimates

[[Page 34049]]

that 6 airplanes of U.S. registry will be affected by this AD.
    It will take approximately 32 work hours (8 work hours per engine) 
per airplane, to accomplish the required thrust reverser inspection, 
modification, and test, described in 747-78A2149, Revision 1, or 
Revision 2, at an average labor rate of $60 per work hour. Based on 
these figures, the cost impact of the AD on U.S. operators is estimated 
to be $11,520, or $1,920 per airplane.
    It will take approximately 8 work hours (2 work hours per engine) 
per airplane, to accomplish the required 1,000-flight-hour inspections 
described in Boeing Service Bulletin 747-78A2159, at an average labor 
rate of $60 per work hour. Based on these figures, the cost impact of 
the inspection required by this AD on U.S. operators is estimated to be 
$2,880, or $480 per airplane, per inspection cycle.
    It will take approximately 20 work hours (5 work hours per engine) 
per airplane, to accomplish the required 18-month thrust reverser 
system checks described in Boeing Service Bulletin 747-78A2159, at an 
average labor rate of $60 per work hour. Based on these figures, the 
cost impact of the test required by this AD on U.S. operators is 
estimated to be $7,200, or $1,200 per airplane, per test cycle.
    It will take approximately 544 work hours per airplane, to 
accomplish the required provisional wiring, at an average labor rate of 
$60 per work hour. Required parts will be provided by the manufacturer 
at no cost to the operators. Based on these figures, the cost impact of 
the AD on U.S. operators is estimated to be $195,840, or $32,640 per 
airplane.
    It will take approximately 593 work hours per airplane, to 
accomplish the required sync lock installation, at an average labor 
rate of $60 per work hour. Required parts will 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 on U.S. operators 
is estimated to be $213,480, or $35,580 per airplane.
    It will take approximately 4 work hours per airplane, to accomplish 
the required functional test of the additional locking system, at an 
average labor rate of $60 per work hour. Based on these figures, the 
cost impact of the test required by this AD on U.S. operators is 
estimated to be $1,680, or $240 per airplane, per test cycle.
    The cost impact figures discussed above are based on assumptions 
that no operator has yet accomplished any of the requirements of this 
AD action, and that no operator would accomplish those actions in the 
future if this AD were not adopted.

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 adding the following new 
airworthiness directive:


2000-10-17 Boeing: Amendment 39-11741. Docket 99-NM-65-AD.

    Applicability: Model 747 series airplanes equipped with Pratt & 
Whitney JT9D-70 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 (g) 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:

Inspection/Repair

    (a) Within 200 flight hours or 50 flight cycles after the 
effective date of this AD, whichever occurs later: Inspect the 
thrust reverser wiring on each engine to detect discrepancies, in 
accordance with Boeing Service Bulletin 747-78A2149, Revision 1, 
dated May 9, 1996, or Revision 2, dated August 29, 1996. Prior to 
further flight, repair any discrepancy, in accordance with the 
service bulletin.

Modification and Tests

    (b) Within 5,000 flight hours or 500 flight cycles after the 
effective date of this AD, whichever occurs later: Accomplish the 
thrust reverser wiring modification on each engine in accordance 
with Boeing Service Bulletin 747-78A2149, Revision 1, dated May 9, 
1996, or Revision 2 dated August 29, 1996.
    (1) Concurrent with accomplishment of Boeing Service Bulletin 
747-78A2149, Revision 1 or Revision 2: Accomplish the modification 
of the thrust reverser control system wiring specified in Rohr 
Service Bulletin TBC-CNS 78-32, Revision 1, dated August 20, 1996.
    (2) Prior to further flight following accomplishment of the 
modification specified in paragraphs (b) and (b)(1): Perform an 
operational test of the thrust reverser wiring on each engine to 
detect discrepancies in accordance with Boeing Service Bulletin 747-
78A2149, Revision 1, dated May 9, 1996, or Revision 2 dated August 
29, 1996. Prior to further flight, correct any discrepancy detected, 
in accordance with the service bulletin.

Repetitive Inspections and Tests

    (c) Perform the inspections and tests of the thrust reverser 
control and indication system to detect discrepancies at the times 
specified in paragraphs (c)(1) and (c)(2) of this AD, in accordance 
with Boeing Alert Service Bulletin 747-78A2159, dated May 18, 1995.
    (1) Within 90 days after the effective date of this AD, inspect 
in accordance with Part III, ``1,000 Flight Hour Inspections'' of 
the Accomplishment Instructions of the alert service bulletin. 
Repeat at intervals not to exceed 1,000 flight hours until 
accomplishment of paragraph (f) of this AD.
    (2) Within 1,500 flight hours or 4 months after the effective 
date of this AD, whichever occurs later, inspect and test in 
accordance with Part III, ``18 Month Thrust Reverser System Checks'' 
of the Accomplishment Instructions of the alert service bulletin. 
Repeat at intervals not to exceed 18 months until accomplishment of 
paragraph (e) of this AD.

[[Page 34050]]

Corrective Actions

    (d) If any inspection or test required by paragraph (c) of this 
AD cannot be successfully performed as specified in the referenced 
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 747-78A2159, dated May 18, 1995. 
Additionally, prior to further flight, any failed inspection or test 
required by paragraph (c) of this AD must be repeated and 
successfully accomplished.

Terminating Action

    (e) Accomplish the requirements of paragraphs (e)(1) and (e)(2) 
of this AD at the times specified in those paragraphs. 
Accomplishment of these actions constitutes terminating action for 
the repetitive inspections and tests required by paragraph (c) of 
this AD.
    (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 747-78-2153, Revision 1, dated November 27, 1996.
    (2) Prior to or concurrent with accomplishment of Boeing Service 
Bulletin 747-78-2153, Revision 1: Accomplish the installation of 
provisional wiring for the locking system on the thrust reversers in 
accordance with Boeing Service Bulletins 747-78-2135, dated August 
31, 1995; and 747-78A2149, Revision 1, dated May 9, 1996, or 
Revision 2, dated August 29, 1996. Additionally, concurrent with 
accomplishment of Boeing Service Bulletin 747-78-2153, Revision 1, 
accomplish the installation of the provisional wiring described 
previously in accordance with Rohr Service Bulletin TBC-CNS 78-33, 
Revision 1, dated August 20, 1996.

Repetitive Functional Tests

    (f) Within 4,000 hours time-in-service after accomplishment of 
paragraph (e) of this AD: Perform a functional test to detect 
discrepancies of the additional locking system on each thrust 
reverser, in accordance with Appendix 1 (including Figures 1 and 2) 
of this AD. Prior to further flight, correct any discrepancy 
detected, in accordance with the procedures described in the Boeing 
747 Airplane Maintenance Manual. Repeat the functional test 
thereafter at intervals not to exceed 4,000 hours time-in-service.

Alternative Methods of Compliance

    (g) 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 Permit

    (h) 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

    (i) Except as provided by paragraph (f) of this AD, the actions 
shall be done in accordance with Boeing Service Bulletin 747-
78A2149, Revision 1, dated May 9, 1996; Boeing Service Bulletin 747-
78A2149, Revision 2, dated August 29, 1996; Boeing Alert Service 
Bulletin 747-78A2159, dated May 18, 1995; Boeing Service Bulletin 
747-78-2135, dated August 31, 1995; Boeing Service Bulletin 747-78-
2153, Revision 1, dated November 27, 1996; Rohr Service Bulletin 
TBC-CNS 78-32, Revision 1, dated August 20, 1996; and Rohr Service 
Bulletin TBC-CNS 78-33, Revision 1, dated August 20, 1996; as 
applicable. Rohr Service Bulletin TBC-CNS 78-32, Revision 1, dated 
August 20, 1996 contains the following list of effective pages:

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                                              Revision level shown on
                 Page No.                               page                        Date shown on page
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1, 3, 5-8, 10-11, 13-14, 16-18............  1..........................  August 20, 1996.
2, 4, 9, 12, 15...........................  Original...................  May 25, 1995.
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    Rohr Service Bulletin TBC-CNS 78-33, Revision 1, dated August 
20, 1996 contains the following list of effective pages:

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                                              Revision level shown on
                 Page No.                               page                        Date shown on page
----------------------------------------------------------------------------------------------------------------
1, 3-55...................................  1..........................  August 20, 1996.
2.........................................  Original...................  December 11, 1995.
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    This incorporation by reference was approved by the Director of 
the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR 
part 51. 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.
    (j) This amendment becomes effective on June 30, 2000.

Appendix 1

Thrust Reverser Sync-Lock Integrity Test

1. General

A. Equipment and Materials

    (1) Thrust reverser flex drive adapter--196K8004-1 or 196K8004-
3; Rohr Industries, Inc., Chula Vista, California 92012.

2. Thrust Reverser Sync-Lock Integrity Test

B. Prepare for the thrust reverser sync lock test.

    (1) Open applicable T/R CONT & BLEED SYS circuit breaker on P12 
circuit breaker panel.
    (2) Open fan cowl doors (Ref 71-11-02, Maintenance Practices).
    (3) Check that forward and aft circumferential latches and all 
tension latches are engaged and locked.
    (4) Depress drive unit latch operating arm and retain by 
engaging latch arm (detail C).
    (5) Disengage stow latch hook on left and right thrust reversers 
(detail D).
    (6) On either lower slave actuator (detail B), either remove 
coverplate from forward drive pad or remove locking plug from lower 
drive pad.
    (7) Move left-hand sync-lock lever to the unlocked position.
    (8) Using appropriate drive adapter (196K8004-1 at forward drive 
pad or 196K8004-3 at lower drive pad), attempt to manually deploy 
sleeves.

CAUTION: DO NOT APPLY A TORQUE LOAD OF MORE THAN 75 POUND-INCHES TO 
THE ACTUATOR; A GREATER TORQUE LOAD CAN CAUSE DAMAGE TO THE 
MECHANISM.

    (9) If sleeves move, replace the right-hand sync-lock.

[[Page 34051]]

    (10) Move left-hand sync-lock lever to the locked position.
    (11) Move right-hand sync-lock lever to the unlocked position.
    (12) Repeat step (8) above.
    (13) If sleeves move, replace the left-hand sync-lock.
    (14) Move left-hand sync-lock lever to the unlocked position.
    (15) Rotate actuator gearshaft to fully stow the sleeves.
    (16) When translating sleeves reach stowed position, check that 
stow latch hooks have engaged fixed hooks on both sides (detail D).
    (17) Depress latch operating arm and disengage latch arm (detail 
C); allow latch arm to raise.
    (18) After releasing arm, verify latch engagement by attempting 
to rotate feedback gear on drive unit using \1/4\-inch square drive; 
gear shall not rotate in excess of 0.1 of a turn.

CAUTION: DO NOT APPLY A TORQUE LOAD OF MORE THAN 25 POUND-INCHES ON 
FEEDBACK GEAR; A GREATER TORQUE LOAD CAN CAUSE DAMAGE TO THE 
MECHANISM.

    (19) As applicable, install locking plug (with square section 
facing away from drive pad) or coverplate on actuator drive pad. 
Secure plug or plate with bolts tightened to 50-70 pound-inches.
    (20) Move both left-and right-hand sync-lock levers to the 
locked position.
    (21) Close fan cowl doors (Ref 71-11-02, Maintenance Practices).
    (22) Close T/R CONT & BLEED SYS circuit breaker.
    (23) Repeat the sync-lock integrity test on all remaining thrust 
reversers.

BILLING CODE 4910-13-U

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[GRAPHIC] [TIFF OMITTED] TR26MY00.036



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    Issued in Renton, Washington, on May 16, 2000.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 00-12812 Filed 5-25-00; 8:45 am]
BILLING CODE 4910-13-C

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