[Federal Register Volume 64, Number 229 (Tuesday, November 30, 1999)]
[Proposed Rules]
[Pages 66816-66820]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-31072]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-108-AD]
RIN 2120-AA64


Airworthiness Directives; McDonnell Douglas Model DC-10 and MD-11 
Series Airplanes, and KC-10A (Military) Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to all McDonnell Douglas Model DC-10 
and MD-11 series airplanes, and KC-10A (military) airplanes. This 
proposal would require installation of thrust reverser interlocks on 
certain airplanes, inspections of the thrust reverser systems to detect 
discrepancies on certain other airplanes, and corrective actions, if 
necessary. This proposal is prompted by a determination that the 
current thrust reverser systems do not adequately preclude unwanted 
deployment of a thrust reverser. The actions specified by the proposed 
AD are intended to prevent unwanted deployment of a thrust reverser, 
which

[[Page 66817]]

could result in reduced controllability of the airplane.

DATES: Comments must be received by January 14, 2000.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 99-NM-108-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except 
Federal holidays.
    The service information referenced in the proposed rule may be 
obtained from Boeing Commercial Aircraft Group, Long Beach Division, 
3855 Lakewood Boulevard, Long Beach, California 90846, Attention: 
Technical Publications Business Administration, Dept. C1-L51 (2-60). 
This information may be examined at the FAA, Transport Airplane 
Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, 
Transport Airplane Directorate, Los Angeles Aircraft Certification 
Office, 3960 Paramount Boulevard, Lakewood, California.

FOR FURTHER INFORMATION CONTACT: Robert Baitoo, Aerospace Engineer, 
Propulsion Branch, ANM-140L, FAA, Transport Airplane Directorate, Los 
Angeles Aircraft Certification Office, 3960 Paramount Boulevard, 
Lakewood, California 90712-4137; telephone (562) 627-5245; fax (562) 
627-5210.

SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed 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 above. All 
communications received on or before the closing date for comments, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained in this notice may be changed in 
light of the comments received.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the proposed 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 summarizing each FAA-public contact concerned with 
the substance of this proposal will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 99-NM-108-AD.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRMs

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules 
Docket No. 99-NM-108-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    Boeing recently completed an update of the System Safety Analysis 
(SSA) for McDonnell Douglas Model DC-10 and MD-11 series airplanes. 
This SSA identified a number of latent (hidden) failures that could 
contribute to unwanted deployment of a thrust reverser in flight. Based 
on this SAA, the FAA has determined that the thrust reverser systems on 
all McDonnell Douglas Model DC-10 and MD-11 series airplanes, and KC-
10A (military) airplanes, do not adequately preclude unwanted 
deployment of a thrust reverser. This condition, if not corrected, 
could result in unwanted deployment of a thrust reverser, which could 
result in reduced controllability of the airplane.

Explanation of Relevant Service Information

    The FAA has reviewed and approved McDonnell Douglas DC-10 Service 
Bulletin 78-40, Revision 1, dated July 24, 1979, which describes 
procedures for installation of thrust reverser interlocks on certain 
Model DC-10-10, -30, and -40 series airplanes. This installation 
includes installing two relays on the forward relay panel and revising 
associated wiring.
    The FAA also has reviewed and approved McDonnell Douglas Alert 
Service Bulletin DC10-78A056, Revision 2, dated February 18, 1999. This 
service bulletin describes procedures for repetitive detailed visual 
inspections, functional checks, and torque checks of the thrust 
reverser systems and the thrust reverser interlocks of certain Model 
DC-10 series airplanes and KC-10A (military) airplanes powered by 
General Electric engines. These inspections and checks are intended to 
detect discrepancies [i.e., below minimum torque required to overcome 
the pneumatic drive motor (PDM) disc brake; cuts, tears, or missing 
sections of the translating cowl seals; dents, cracks, holes, or loose 
fasteners on the Dagmar fairing or aft frame; improper alignment of the 
feedback rod; hidden faults in the translating cowl auto re-stow 
system; a failed over pressure shutoff valve (OPSOV); and improper 
operation of the fan reverser actuation system].
    McDonnell Douglas Alert Service Bulletin DC10-78A056, Revision 2, 
dated February 18, 1999, references Middle River Aircraft Systems 
(MRAS) Service Bulletins (S/B) 78-3001, Revision 2, dated December 18, 
1997, and S/B 78-2004, Revision 1, dated December 18, 1997, as 
additional sources of service information for accomplishment of the 
inspections and corrective actions. The corrective actions include 
replacement of the discrepant parts or deactivation of the thrust 
reversers.
    The FAA also has reviewed and approved McDonnell Douglas Alert 
Service Bulletin DC10-78A057, Revision 1, dated February 18, 1999. This 
service bulletin describes procedures for repetitive detailed visual 
inspections, functional checks, and torque checks of the thrust 
reverser systems on certain Model DC-10-40 series airplanes powered by 
Pratt & Whitney engines. These inspections and checks are intended to 
detect discrepancies (i.e., damaged or improperly functioning stow 
latch hooks; cuts, gouges, or holes in the pneumatic seal/bullnose 
seal; improper functioning of the pneumatic drive unit (PDU) position 
locking retention feature; improper installation or improper operation 
of the system wiring, switches, or indicator lights; damage to the fan 
reverser flexshafts, actuators, or translating sleeve tracks or 
sliders; improper function of the in-flight interlock system; and 
improper operation of the thrust reverser power source, translating 
sleeve, throttle interlocks, or cockpit indicators). The alert service 
bulletin specifies that corrective actions for discrepancies found 
during these actions are to be accomplished in accordance with normal 
maintenance practices.
    The FAA also has reviewed and approved McDonnell Douglas MD-11 
Certification Maintenance Requirements (CMR), Revision P, dated April 
5, 1999, which, among other things, describes procedures for repetitive 
inspections and tests for all MD-11 thrust reverser systems. The 
procedures include inspection of the cone brake within the Center Drive 
Unit (CDU) to detect slipping or a failed CDU brake; and functional 
tests of the two position microswitches on the CDU and their associated 
wiring to detect failed open

[[Page 66818]]

switches or open wire runs. These procedures also include inspection of 
the aerodynamic seal between the reverser translating sleeves and the 
main reverser structure to detect damage to the aerodynamic seal or its 
interface surface on the reverser structure; and functional tests of 
the thrust reverser In-Flight Lockout System (IFLS) to detect failure 
of the flight control computer (FCC), radio altimeter input to the FCC, 
main landing gear wheel speed input to the FCC, ground sensing system, 
or wiring that causes an on-ground status in the IFLS while the 
aircraft is airborne. These procedures also include inspections to 
detect failed open pressure switches on the hydraulic control unit, 
failed stow position microswitches, or failed locking mechanisms. In 
addition, the procedures include testing of the thrust reverser 
pressurization system to detect an uncommanded pressurized thrust 
reverser system and/or a failed thrust reverser pressure switch, as 
applicable. Corrective actions for discrepancies found during these 
actions are to be accomplished in accordance with normal maintenance 
practices.
    The FAA also has reviewed and approved MRAS Alert Service Bulletin 
CF6-80C2D1F SB 78A1082, dated August 25, 1999. This service bulletin 
describes procedures for a pressure differential inspection of the 
directional pilot valves (DPV) on the thrust reverser systems to detect 
a partially open solenoid or failed O-ring, and corrective actions, if 
necessary. The corrective actions include replacement of a discrepant 
DPV with a DPV that has been inspected, or deactivation of the thrust 
reverser. In lieu of accomplishing the inspection, this service 
bulletin also describes procedures for replacement of a DPV with a DPV 
that has been inspected.
    The FAA also has reviewed and approved documents which describe 
corrective actions for the discrepancies specified above, as 
applicable:
     Chapter 78 of McDonnell Douglas DC-10 Aircraft Maintenance 
Manual (AMM);
     Chapter 78 of McDonnell Douglas DC-10 Turn Around Fault 
Isolation Manual (TAFIM);
     Chapter 78 of General Electric Shop Manual;
     MRAS Service Bulletin 78-2004, Revision 1, dated December 
18, 1997;
     MRAS Service Bulletin 78-3001 Revision 2, dated December 
18, 1997;
     McDonnell Douglas Alert Service Bulletin DC10-78A056, 
dated January 1, 1998, Revision 1, dated June 4, 1998, or Revision 2, 
dated February 18, 1999;
     McDonnell Douglas Alert Service Bulletin DC10-78A057, 
dated November 30, 1998, or Revision 1, dated February 18, 1999;
     Chapters 71 and 78 of McDonnell Douglas MD-11 Aircraft 
Maintenance Manual; and
     Chapter 78 of McDonnell Douglas MD-11 Fault Isolation 
Manual (FIM).
    Accomplishment of the actions specified in the service bulletins, 
CMR, and Master Minimum Equipment Lists (MMEL) is intended to 
adequately address the identified unsafe condition.

Explanation of Requirements of Proposed Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other products of this same type design, the 
proposed AD would require accomplishment of the actions specified in 
the service information described previously, except as discussed 
below.

Differences Between the Proposed Rule and the Relevant Service 
Information

    Operators should note that, although McDonnell Douglas DC-10 
Service Bulletin 78-40, Revision 1, dated July 24, 1979, recommends 
accomplishing the modification at the ``operator's convenience'', the 
FAA has determined that this would not address the identified unsafe 
condition in a timely manner. In developing an appropriate compliance 
time for this AD, the FAA considered not only the manufacturer's 
recommendation, but the degree of urgency associated with addressing 
the subject unsafe condition, the average utilization of the affected 
fleet, and the time necessary to perform the modification (less than 10 
hours). In light of all of these factors, the FAA finds a compliance 
time of within 1,500 flight hours or 6 months after the effective date 
of this AD, whichever occurs first, for initiating the proposed actions 
to be warranted, in that it represents an appropriate interval of time 
allowable for affected airplanes to continue to operate without 
compromising safety.
    Additionally, operators should note that the applicability of 
paragraphs (b) and (c) of the proposed AD differs from the effectivity 
listing specified in McDonnell Douglas DC-10 Service Bulletin 78-40, 
Revision 1, dated July 24, 1979. Some of the airplanes that are listed 
in McDonnell Douglas DC-10 Service Bulletin 78-40, Revision 1, dated 
July 24, 1979, have been removed from service. Therefore, those 
airplanes are not included in the applicability of paragraphs (b) and 
(c) of the proposed AD.

Interim Action

    For all Model DC-10 series airplanes, this is considered to be 
interim action. The manufacturer has advised that it currently is 
developing a modification that will positively address the unsafe 
condition addressed by this AD. Once this modification is developed, 
approved, and available, the FAA may consider additional rulemaking.

Cost Impact

    There are approximately 259 Model DC-10-10, -30, and -40 series 
airplanes and KC-10A (military) airplanes of the affected design in the 
worldwide fleet that are listed in McDonnell Douglas DC-10 Service 
Bulletin 78-40, Revision 1, dated July 24, 1979. The FAA estimates that 
135 airplanes of U.S. registry would be affected by this proposed AD, 
that it would take approximately 10 work hours per airplane to 
accomplish the proposed actions related to this service bulletin, and 
that the average labor rate is $60 per work hour. The required parts 
would be obtained from the operator's stock. Based on these figures, 
the cost impact of this portion of the proposed AD on U.S. operators is 
estimated to be $81,000, or $600 per airplane.
    There are approximately 359 Model DC-10-10, -15, -30, and -40 
series airplanes and KC-10A (military) airplanes of the affected design 
in the worldwide fleet that are listed in McDonnell Douglas Alert 
Service Bulletin DC10-78A056, Revision 2, dated February 18, 1999. The 
FAA estimates that 187 airplanes of U.S. registry would be affected by 
this proposed AD, that it would take approximately 5 work hours per 
airplane to accomplish the proposed actions related to this service 
bulletin, and that the average labor rate is $60 per work hour. Based 
on these figures, the cost impact of this portion of the proposed AD on 
U.S. operators is estimated to be $56,100, or $300 per airplane, per 
inspection cycle.
    There are approximately 41 Model DC-10-40 series airplanes of the 
affected design in the worldwide fleet that are listed in McDonnell 
Douglas Alert Service Bulletin DC10-78A057, Revision 1, dated February 
18, 1999. The FAA estimates that 22 airplanes of U.S. registry would be 
affected by this proposed AD, that it would take approximately 31 work 
hours per airplane to accomplish the proposed actions related to this 
service bulletin, and that the average labor rate is $60 per work hour. 
Based on these figures, the cost impact of this portion of the proposed 
AD on U.S. operators is

[[Page 66819]]

estimated to be $40,920, or $1,860 per airplane, per inspection cycle.
    There are approximately 165 Model MD-11 airplanes of the affected 
design in the worldwide fleet that are equipped with General Electric 
engines. The FAA estimates that 86 airplanes of U.S. registry would be 
affected by this proposed AD, that it would take approximately 6 work 
hours per airplane to accomplish the proposed actions, and that the 
average labor rate is $60 per work hour. Based on these figures, the 
cost impact of this portion of the proposed AD on U.S. operators is 
estimated to be $30,960, or $360 per airplane, per inspection cycle.
    There are approximately 19 Model MD-11 airplanes of the affected 
design in the worldwide fleet that are equipped with Pratt & Whitney 
engines. The FAA estimates that 5 airplanes of U.S. registry would be 
affected by this proposed AD, that it would take approximately 31 work 
hours per airplane to accomplish the proposed actions, and that the 
average labor rate is $60 per work hour. Based on these figures, the 
cost impact of this portion of the proposed AD on U.S. operators is 
estimated to be $9,300, or $1,860 per airplane, per inspection cycle.
    The cost impact figures discussed above are based on assumptions 
that no operator has yet accomplished any of the proposed 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 proposed herein would 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 
proposal would not have sufficient federalism implications to warrant 
the preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this proposed 
regulation (1) is not a ``significant regulatory action'' under 
Executive Order 12866; (2) is not a ``significant rule'' under the DOT 
Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); 
and (3) if promulgated, 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 copy of the draft 
regulatory evaluation prepared for this action is contained in the 
Rules Docket. A copy of it may be obtained by contacting the Rules 
Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 
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:

McDonnell Douglas: Docket 99-NM-108-AD.

    Applicability: All Model DC-10 series airplanes, MD-11 series 
airplanes, and KC-10A (military) airplanes; 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 (j) 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 unwanted deployment of the thrust reverser, which 
could result in reduced controllability of the airplane, accomplish 
the following:

Modification of Certain Model DC-10 Series Airplanes

    (a) For Model DC-10-10, -30, and -40 series airplanes listed in 
McDonnell Douglas DC-10 Service Bulletin 78-40, Revision 1, dated 
July 24, 1979: Within 1,500 flight hours or 6 months after the 
effective date of this AD, whichever occurs first, install a thrust 
reverser interlock (in-flight lockout) by installing two relays on 
the forward relay panel and revising the associated wiring, in 
accordance with the service bulletin. The requirements of this 
paragraph must be accomplished prior to or in conjunction with the 
requirements of paragraph (b) or (c) of this AD, as applicable.

Inspection of Model DC-10 Airplanes Powered by General Electric Engines

    (b) For DC-10-10, -15, -30, and -40 series airplanes listed in 
McDonnell Douglas Alert Service Bulletin DC10-78A056, Revision 2, 
dated February 18, 1999: Within 1,500 flight hours or 6 months after 
the effective date of this AD, whichever occurs first, perform a 
detailed visual inspection, functional check, and torque checks of 
the thrust reverser system and the thrust reverser interlocks to 
detect discrepancies [i.e., below minimum torque required to 
overcome the pneumatic drive motor (PDM) disc brake; cuts, tears, or 
missing sections of the translating cowl seals; dents, cracks, 
holes, or loose fasteners on the Dagmar fairing or aft frame; 
improper alignment of the feedback rod; hidden faults in the 
translating cowl auto re-stow system; a failed over pressure shutoff 
valve (OPSOV); and improper operation of the fan reverser actuation 
system], in accordance with the service bulletin. Repeat the 
inspections at intervals not to exceed 6,000 flight hours or 18 
months, whichever occurs first.

    Note 2: For the purposes of this AD, a detailed visual 
inspection is defined as: ``An intensive visual examination of a 
specific structural area, system, installation, or assembly to 
detect damage, failure, or irregularity. Available lighting is 
normally supplemented with a direct source of good lighting at 
intensity deemed appropriate by the inspector. Inspection aids such 
as mirror, magnifying lenses, etc., may be used. Surface cleaning 
and elaborate access procedures may be required.''
    Note 3: Inspection of the thrust reverser system accomplished 
prior to the effective date of this AD in accordance with McDonnell 
Douglas Alert Service Bulletin DC10-78A056, dated January 19, 1998, 
or Revision 1, dated June 4, 1998, is considered acceptable for 
compliance with the initial inspections required by paragraph (b) of 
this AD.

    Note 4: McDonnell Douglas Alert Service Bulletin DC10-78A056, 
Revision 2, dated February 18, 1999, references Middle River 
Aircraft Systems (MRAS) Service Bulletin (S/B) 78-3001, Revision 2, 
dated December 18, 1997, and MRAS S/B 78-2004, Revision 1, dated 
December 18, 1997, as additional sources of service information for 
accomplishment of the inspections and corrective actions.

Inspection of Model DC-10-40 Series Airplanes Powered by Pratt & 
Whitney Engines

    (c) For Model DC-10-40 series airplanes listed in McDonnell 
Douglas Alert Service Bulletin DC10-78A057, Revision 01, dated 
February 18, 1999: Within 1,500 flight hours or 6 months after the 
effective date of this AD, whichever occurs first, perform a 
detailed visual inspection, functional check, and torque checks of 
the thrust reverser system to detect discrepancies [i.e. damaged or 
improperly functioning stow latch hooks; cuts, gouges, and holes in 
the pneumatic seal/bullnose seal; improper functioning of the PDU 
position locking retention feature; improper installation or 
improper operation of the system wiring, switches, or indicator 
lights; damage to the fan reverser flexshafts,

[[Page 66820]]

actuators, translating sleeve tracks, or sliders; improper function 
of the in-flight interlock system; and improper operation of the 
thrust reverser power source, translating sleeve, throttle 
interlocks, or cockpit indicators], in accordance with the service 
bulletin. Repeat the inspections thereafter at intervals not to 
exceed 6,000 flight hours or 18 months, whichever occurs first.

    Note 5: Inspection of the thrust reverser system in accordance 
with McDonnell Douglas Alert Service Bulletin DC10-78A057, dated 
November 30, 1998, accomplished prior to the effective date of this 
AD, is considered acceptable for initial compliance with the 
applicable action specified in paragraph (c) of this AD.

Inspection of Model MD-11 Series Airplanes Powered by General Electric 
Engines

    (d) For Model MD-11 series airplanes equipped with General 
Electric engines: Perform a detailed visual inspection and 
functional check of the two position microswitches on the Center 
Drive Unit (CDU) and their associated wiring to detect failed open 
switches or open wire runs, and the aerodynamic seal between the 
reverser translating sleeves and the main reverser structure to 
detect damage to the aerodynamic seal or its interface surface on 
the reverser structure; and perform an inspection to determine the 
torque value of the cone brake within the CDU to detect slipping or 
a failed CDU brake. These inspections and functional check shall be 
done in accordance with pages 17 and 18 of the McDonnell Douglas MD-
11 Certification Maintenance Requirements (CMR), Revision P, dated 
April 5, 1999; at the times specified in paragraph (d)(1) or (d)(2) 
of this AD, as applicable.
    (1) For airplanes on which the modification (i.e., translating 
cowl double P-seal configuration) specified in Lockheed Martin/
Middle River Aircraft Systems (MRAS) Service Bulletin 78A1005, dated 
March 29, 1995; Revision 1, dated June 6, 1996; Revision 2, dated 
October 18, 1996; Revision 3, dated August 18, 1997; or Revision 4, 
dated December 21, 1998; has been accomplished: Inspect within 7,000 
flight hours after the effective date of this AD. Repeat the 
inspections thereafter at intervals not to exceed 7,000 flight 
hours.
    (2) For airplanes on which the modification (i.e., translating 
cowl double P-seal configuration) specified in MRAS Service Bulletin 
78A1005, dated March 29, 1995; Revision 1, dated June 6, 1996; 
Revision 2, dated October 18, 1996; Revision 3, dated August 18, 
1997; or Revision 4, dated December 21, 1998; has not been 
accomplished: Inspect within 2,000 flight hours after the effective 
date of this AD. Repeat the inspections thereafter at intervals not 
to exceed 2,000 flight hours.
    (e) For Model MD-11 series airplanes equipped with General 
Electric engines, without an Electronic Control Unit (ECU), part 
number 1519M91P06, installed: Within 2,000 flight hours after the 
effective date of this AD, test the thrust reverser pressurization 
system to detect an uncommanded pressurized thrust reverser system 
and/or a failed thrust reverser pressure switch, as applicable, in 
accordance with pages 52 and 53 of the McDonnell Douglas MD-11 CMR, 
Revision P, dated April 5, 1999. Repeat the inspections thereafter 
at intervals not to exceed 2,000 flight hours.
    (f) For Model MD-11 series airplanes equipped with General 
Electric engines: Within 7,000 flight hours after the effective date 
of this AD, inspect the thrust reverser In-Flight Lockout System 
(IFLS) to detect failure of the flight control computer (FCC), radio 
altimeter input to the FCC, main landing gear wheel speed input to 
the FCC, ground sensing system, or wiring that causes an on-ground 
status in the IFLS while the aircraft is airborne, in accordance 
with page 54 of the McDonnell Douglas MD-11 Certification 
Maintenance Requirements (CMR), Revision P, dated April 5, 1999. 
Repeat the inspections thereafter at intervals not to exceed 7,000 
flight hours.
    (g) For Model MD-11 series airplanes equipped with General 
Electric engines: Within 600 flight hours after the effective date 
of this AD, accomplish the actions specified in paragraph (g)(1), 
(g)(2), or (g)(3) of this AD in accordance with MRAS Alert Service 
Bulletin CF6-80C2D1F SB 78A1082, dated August 25, 1999.
    (1) Perform a pressure differential inspection of the 
directional pilot valves (DPV) to detect a partially open solenoid 
or failed O-ring. If any partially open solenoid or failed O-ring is 
detected, prior to further flight, replace the discrepant DPV with a 
DPV that has been inspected in accordance with this paragraph. 
Repeat the inspection thereafter at intervals not to exceed 2,000 
flight hours. Or
    (2) Replace the DPV with a DPV that has been inspected in 
accordance with paragraph (g)(1) of this AD. Repeat the replacement 
thereafter at intervals not to exceed 2,000 flight hours. Or
    (3) Deactivate the thrust reverser in accordance with the MD-11 
Master Minimum Equipment List, and reactivate the thrust only after 
accomplishing the actions specified in paragraph (g)(1) or (g)(2) of 
this AD.

Inspection of Model MD-11 Series Airplanes Powered by Pratt & Whitney 
Engines

    (h) For MD-11 series airplanes equipped with Pratt & Whitney 
engines: Within 7,000 flight hours after the effective date of this 
AD, perform a detailed visual inspection and functional checks, as 
applicable, of the thrust reverser system and the thrust reverser 
In-Flight Lockout System to detect failed open pressure switches on 
the hydraulic control unit, to detect failed stow position 
microswitches, or failed locking mechanisms; and failure of the FCC, 
radio altimeter input to the FCC, main landing gear wheel speed 
input to the FCC, ground sensing system, or wiring that causes an 
on-ground status in the IFLS while the aircraft is airborne, in 
accordance with pages 19, 20, and 54 of the McDonnell Douglas MD-11 
Certification Maintenance Requirements CMR, Revision P, dated April 
5, 1999. Repeat the inspections thereafter at intervals not to 
exceed 7,000 flight hours.

Corrective Actions

    (i) If any discrepancy is detected during any inspection 
required by this AD, prior to further flight, accomplish the actions 
specified in either paragraph (i)(1) or (i)(2) of this AD.
    (1) Perform applicable corrective action in accordance with the 
following service documents:
     Chapter 78 of McDonnell Douglas DC-10 Aircraft 
Maintenance Manual;
     Chapter 78 of McDonnell Douglas DC-10 Turn Around Fault 
Isolation Manual; Chapter 78 of General Electric Shop Manual;
     MRAS Service Bulletin 78-2004, Revision 1, dated 
December 18, 1997;
     MRAS Service Bulletin 78-3001 Revision 2, dated 
December 18, 1997;
     McDonnell Douglas Alert Service Bulletin DC10-78A056, 
dated January 1, 1998, Revision 1, dated June 4, 1998, or Revision 
2, dated February 18, 1999;
     McDonnell Douglas Alert Service Bulletin DC10-78A057, 
dated November 30, 1998, or Revision 1, dated February 18, 1999;
     Chapters 71 and 78 of McDonnell Douglas MD-11 Aircraft 
Maintenance Manual;
     Chapter 78 of McDonnell Douglas MD-11 Fault Isolation 
Manual; or
     A method approved by the Manager, Los Angeles Aircraft 
Certification Office (ACO), FAA, Transport Airplane Directorate.
    (2) Deactivate the thrust reverser in accordance with the DC-10 
Master Minimum Equipment List or the MD-11 Master Minimum Equipment 
List, as applicable.

Alternative Methods of Compliance

    (j) 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, Los Angeles ACO. Operators shall 
submit their requests through an appropriate FAA Principal 
Maintenance Inspector, who may add comments and then send it to the 
Manager, Los Angeles ACO.

    Note 6: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Los Angeles ACO.

Special Flight Permits

    (k) 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.

    Issued in Renton, Washington, on November 23, 1999.
D.L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 99-31072 Filed 11-29-99; 8:45 am]
BILLING CODE 4910-13-U