Airworthiness directives: McDonnell Douglas,
[Federal Register: November 30, 1999 (Volume 64, Number 229)]
[Proposed Rules]
[Page 66816-66820]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr30no99-31]
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).
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
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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 filedin 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
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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:
‹bullet› Chapter 78 of McDonnell Douglas DC-10 Aircraft Maintenance Manual (AMM);
‹bullet› Chapter 78 of McDonnell Douglas DC-10 Turn Around Fault Isolation Manual (TAFIM);
‹bullet› Chapter 78 of General Electric Shop Manual;
‹bullet› MRAS Service Bulletin 78-2004, Revision 1, dated December 18, 1997;
‹bullet› MRAS Service Bulletin 78-3001 Revision 2, dated December 18, 1997;
‹bullet› McDonnell Douglas Alert Service Bulletin DC10-78A056, dated January 1, 1998, Revision 1, dated June 4, 1998, or Revision 2, dated February 18, 1999;
‹bullet› McDonnell Douglas Alert Service Bulletin DC10-78A057, dated November 30, 1998, or Revision 1, dated February 18, 1999;
‹bullet› Chapters 71 and 78 of McDonnell Douglas MD-11 Aircraft Maintenance Manual; and
‹bullet› 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
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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
-
The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
-
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,
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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:
‹bullet› Chapter 78 of McDonnell Douglas DC-10 Aircraft Maintenance Manual;
‹bullet› Chapter 78 of McDonnell Douglas DC-10 Turn Around Fault Isolation Manual; Chapter 78 of General Electric Shop Manual;
‹bullet› MRAS Service Bulletin 78-2004, Revision 1, dated December 18, 1997;
‹bullet› MRAS Service Bulletin 78-3001 Revision 2, dated December 18, 1997;
‹bullet› McDonnell Douglas Alert Service Bulletin DC10-78A056, dated January 1, 1998, Revision 1, dated June 4, 1998, or Revision 2, dated February 18, 1999;
‹bullet› McDonnell Douglas Alert Service Bulletin DC10-78A057, dated November 30, 1998, or Revision 1, dated February 18, 1999;
‹bullet› Chapters 71 and 78 of McDonnell Douglas MD-11 Aircraft Maintenance Manual;
‹bullet› Chapter 78 of McDonnell Douglas MD-11 Fault Isolation Manual; or
‹bullet› 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. 99-31072Filed11-29-99; 8:45 am]
BILLING CODE 4910-13-U
