[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