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92-24-02: 92-24-02 DE HAVILLAND: Amendment 39-8407. Docket No. 91-CE-93-AD. Applicability: Model DHC-2 Beaver MK-I, MK-II, and MK-III airplanes (all serial numbers), certificated in any category. Compliance: Required as indicated, unless already accomplished. To prevent horizontal stabilizer front center spar failure, which could lead to loss of control of the airplane, accomplish the following: NOTE 1: The compliance times specified in this AD take precedence over those referenced in the service information. (a) Within the next 4 calendar months after the effective date of this AD, accomplish the following: (1) Dye penetrant inspect the horizontal stabilizer front center spar for cracks in accordance with paragraphs 1, 2, and 3 of Part A. of the ACCOMPLISHMENT INSTRUCTIONS section of de Havilland Service Bulletin (SB) 2/47, Revision C, dated September 4, 1992. (i) If no cracks are found, accomplish the requirements of paragraph (a)(2) of this AD oraccomplish the requirements of paragraph 5 of Part A. of the ACCOMPLISHMENT INSTRUCTIONS section of de Havilland SB 2/47, Revision C, dated September 4, 1992, whichever is applicable. (ii) If cracks are found on airplanes not having a gusset plate installed on the rear face of the horizontal stabilizer front center spar (Pre-Modification 2/758), prior to further flight, replace the horizontal stabilizer front center spar in accordance with Part B. of the ACCOMPLISHMENT INSTRUCTIONS section of de Havilland SB 2/47, Revision C, dated September 4, 1992. (iii) If cracks are found on airplanes that have a gusset plate installed on the rear face of the horizontal stabilizer front center spar (Post-Modification 2/758), within the next 8 calendar months, replace the horizontal stabilizer front center spar in accordance with Part B. of the ACCOMPLISHMENT INSTRUCTIONS section of de Havilland SB 2/47, Revision C, dated September 4, 1992. (2) For airplanes that have lighteningholes in the horizontal stabilizer front center spar (Pre-Modification 2/466) and that did not have the horizontal stabilizer front center spar replaced as required by either paragraph (a)(1)(ii) or (a)(1)(iii) of this AD, visually inspect the front spar web for cracks in accordance with paragraph 4 of Part A. of the ACCOMPLISHMENT INSTRUCTIONS section of de Havilland SB 2/47, Revision C, dated September 4, 1992. (i) If no cracks are found, accomplish the requirements of paragraph 5 of Part A. of the ACCOMPLISHMENT INSTRUCTIONS section of de Havilland SB 2/47, Revision C, dated September 4, 1992. (ii) If any cracks are found, prior to further flight, replace the horizontal stabilizer front center spar in accordance with Part B. of the ACCOMPLISHMENT INSTRUCTIONS section of de Havilland SB 2/47, Revision C, dated September 4, 1992. NOTE 2: De Havilland SB 2/47, Revision C, dated September 4, 1992, references both the horizontal stabilizer front center spar and the tailplane front center spar. These are one and the same. For the purposes of this AD, all reference is to the horizontal stabilizer front center spar. (b) If any previously stop-drilled cracks are found per the inspections specified in paragraphs (a)(1) and (a)(2) of this AD, within the following time frames, replace the horizontal stabilizer front center spar in accordance with Part B. of the ACCOMPLISHMENT INSTRUCTIONS section of de Havilland SB 2/47, Revision C, dated September 4, 1992, unless already accomplished in accordance with either paragraph (a)(1)(ii), (a)(1)(iii), or (a)(2)(ii) of this AD: (1) Within the next 12 calendar months if the stop-drilled cracks have not progressed past the stop. (2) Within the next 8 calendar months if the stop-drilled cracks have progressed past the stop and the airplane has a gusset plate installed on the rear face of the horizontal stabilizer front center spar (Post-Modification 2/758). (3) Prior to further flight if thestop-drilled cracks have progressed past the stop and the airplane does not have a gusset plate installed on the rear face of the horizontal stabilizer front center spar (Pre-Modification 2/758). (c) Within the next 24 calendar months after the effective date of this AD, accomplish the following: (1) For airplanes having serial numbers (S/N) 1 through 100, install longer pick-up brackets (Modification 2/436) in accordance with the instructions in de Havilland Technical News Sheet B55, dated August 1, 1952, unless already incorporated. NOTE 3: Modification 2/436 was incorporated at manufacture on airplanes beginning with S/N 101. Other airplanes may have incorporated this modification in the field. (2) For airplanes having S/N 1 through 317, install a gusset plate on the rear face at each of the pick-up brackets (Modification 2/758) in accordance with the instructions in de Havilland Technical News Sheet B55, dated August 1, 1952, unless already incorporated.NOTE 4: Modification 2/758 was incorporated at manufacture on airplanes beginning with S/N 318. Other airplanes may have incorporated this modification in the field. NOTE 5: Modification 2/466 - installation of tailplane front spar without lightening holes - is referenced in de Havilland SB 2/47, Revision C, dated September 4, 1992. Accomplishment of this AD incorporates this modification. (d) Within the next 24 calendar months after the effective date of this AD or within 24 calendar months after accomplishing the requirements of paragraph (c) of this AD, whichever occurs later, and thereafter at intervals not to exceed 24 calendar months, visually inspect the front face of the horizontal stabilizer front center spar for cracks. If any cracks are found, prior to further flight, obtain a repair scheme from the manufacturer through the New York Aircraft Certification Office at the address specified in paragraph (f) of this AD, and accomplish the repair in accordance with the repair scheme obtained. (e) Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate the airplane to a location where the requirements of this AD can be accomplished. (f) An alternative method of compliance or adjustment of the compliance times that provides an equivalent level of safety may be approved by the Manager, New York Aircraft Certification Office, 181 South Franklin Avenue, Room 202, Valley Stream, New York 11581. The request shall be forwarded through an FAA Maintenance Inspector, who may add comments and then send it to the Manager, New York Aircraft Certification Office. NOTE 6: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the New York Aircraft Certification Office. (g) The inspections and modifications required by this AD shall be done in accordance with de Havilland Service Bulletin 2/47, Revision C, dated September 4, 1992; and deHavilland Technical News Sheet B55, dated August 1, 1952. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51. Copies may be obtained from de Havilland, Inc., Downsview, Ontario, Canada, M2K 1Y5. Copies may be inspected at the FAA, Central Region, Office of the Assistant Chief Counsel, Room 1558, 601 E. 12th Street, Kansas City, Missouri, or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. (h) This amendment becomes effective on December 15, 1992.
82-17-03: 82-17-03 SIKORSKY AIRCRAFT: Amendment 39-4437. Applies to Sikorsky Model S-76A helicopters, equipped with rotor brake systems, certificated in all categories. Compliance is required as indicated, unless already accomplished. To prevent the possibility of fire due to a malfunctioning rotor brake, accomplish the following: (a) Within the next 10 hours' time in service after the effective date of the AD on aircraft equipped with P/N 76363-09101-101 rotor brake: (1) Prior to each flight whenever the rotor brake has previously been applied, inspect puck-to-disk clearance for .045 inch minimum at all 4 pucks. (2) If the puck-to-disk clearance is less than .045 inch, remove rotor brake assembly and replace with a serviceable unit. (b) Within the next 90 days after the effective date of the AD, unless already accomplished: (1) Modify the No. 2 relay panel assembly in accordance with the Accomplishment Instructions, Paragraph 2, of Sikorsky Customer Service Bulletin No. 76-66-7, dated March 9, 1981, or FAA approved equivalent. (2) Modify the brake installation by the addition of shield assemblies in accordance with the Accomplishment Instructions, Paragraph 2, of Sikorsky Customer Service Bulletin No. 76-66-8A, dated September 30, 1981, or FAA approved equivalent. NOTE: After installation of the shield assemblies, the supplementary installation of an access door in the upper rotor brake shield, in accordance with Sikorsky Customer Service Notice No. 76-79, dated December 23, 1981, or later FAA approved revision, may be accomplished at the operator's option. (3) Install a warning relay in accordance with the Accomplishment Instructions, Paragraph 2, of Sikorsky Customer Service Bulletin No. 76-66-10B, dated November 25, 1981, or FAA approved equivalent. (4) Modify Sikorsky P/N 76363-09101-101 brake by the installation of torqueless grip adjusters, Goodyear P/N 9522164, in accordance with Sikorsky Customer Service Notice No. 76-51B, dated April 22, 1982, or FAA approved equivalent, and Customer Service Letter CSL-SPT-82-089, dated May 20, 1982, or FAA approved equivalent. Reassemble and test in accordance with Paragraph B and C of Sikorsky Customer Service Notice No. 76-51B, dated April 22, 1982, or FAA approved equivalent. (c) After compliance with paragraph (b) of the AD, the inspection prescribed by paragraph (a)(1) above is no longer required. (d) Equivalent means of compliance may be approved by the Chief, Boston Aircraft Certification Branch, Federal Aviation Administration, New England Region, 12 New England Executive Park, Burlington, Massachusetts 01803. This amendment becomes effective August 23, 1982.
86-20-08: 86-20-08 MCDONNELL DOUGLAS: Amendment 39-5434. Applies to McDonnell Douglas Model DC-8 series -10 through -50, -61, -61F, -71, and -71F airplanes with left and/or right wing front spar lower cap Part Numbers 5597838-1, -2, not modified in accordance with McDonnell Douglas DC-8 Service Bulletin 57-90, dated October 3, 1983, certificated in any category. Compliance required as indicated. \n\n\tTo prevent the loss of structural integrity of the left and/or right wing due to metal fatigue failure of the front spar lower cap, prior to the accumulation of 30,000 flight-hours or within 200 flight-hours after the effective date of this AD, whichever occurs later, accomplish the following, unless already accomplished within the last 3,400 flight-hours: \n\n\tA.\tVisually or eddy current inspect left and right wing front spar lower cap, P/N's 5597838-1, -2, between Stations Xfs = 515.000 and Xfs = 526.760 for cracks in accordance with paragraph 2.B. of McDonnell Douglas DC-8 Service Bulletin57-90 dated October 3, 1983, or later FAA-approved revisions. \n\n\tB.\tIf no crack is found, accomplish repetitive inspections on the spar cap in accordance with paragraph A. of this AD, at intervals not to exceed 3,600 flight-hours or one calendar year, whichever occurs first. \n\n\tC.\tIf crack(s) are found, before further flight: \n\n\t\t1.\tFor cracks within repairable limits, as defined by paragraph 2.B. of DC-8 Service Bulletin 57-90, repair cracked spar cap in accordance with paragraph 2.B. of that service bulletin. \n\n\t\t2.\tFor cracks greater than those specified by the above service bulletin, repair in a manner approved by the Manager, Los Angeles Aircraft Certification Office, FAA, Northwest Mountain Region. \n\n\tD.\tModification of the attach holes in the forward tang of the front spar lower cap in accordance with paragraph 2.B. of DC-8 Service Bulletin 57-90 constitutes terminating action for the repetitive inspection requirements in paragraph B. of this AD. \n\n\tE.\tAlternate means of compliance which provide an equivalent level of safety may be used when approved by the Manager, Los Angeles Aircraft Certification Office, FAA, Northwest Mountain Region. \n\n\tF. \tSpecial flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base in order to comply with the requirements of this AD. \n\n\tAll persons affected by this directive who have not already received the appropriate service documents from the manufacturer may obtain copies upon request to McDonnell Douglas Corporation, 3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Director, Publications and Training, C1-L65 (54-60). These documents also may be examined at the FAA, Northwest Mountain Region, 17900 Pacific Highway South, Seattle, Washington, or the Los Angeles Aircraft Certification Office, 4344 Donald Douglas Drive, Long Beach, California. \n\n\tThis Amendment becomes effective October 20, 1986.
2000-02-22: This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing Model 747-400 series airplanes. This action requires installation of a modification of the thrust reverser control and indication system and wiring on each engine; and repetitive operational checks of that installation to detect discrepancies, and repair, if necessary. This amendment is prompted by the results of a safety review, which revealed that in-flight deployment of a thrust reverser could result in a significant reduction in airplane controllability. The actions specified in this AD are intended to ensure the integrity of the fail-safe features of the thrust reverser system by preventing possible failure modes, which could result in inadvertent deployment of a thrust reverser during flight, and consequent reduced controllability of the airplane.
2019-18-02: The FAA is adopting a new airworthiness directive (AD) for certain Leonardo S.p.A. (Leonardo) Model AW169 helicopters. This AD requires replacing the seals, filler wedges, and handles of each emergency exit window. This AD was prompted by a report that a high level of pushing force was required to jettison some windows. The actions of this AD are intended to address an unsafe condition on these products.
95-20-04: This amendment adopts a new airworthiness directive (AD), applicable to all Lockheed Model L-1011-385-1 series airplanes, that requires implementation of a Supplemental Inspection Document (SID) program of structural inspections to detect fatigue cracking, and repair, if necessary, to ensure continued airworthiness of these airplanes as they approach the manufacturer's original fatigue design life goal. This amendment is prompted by a structural re-evaluation by the manufacturer that identified certain structural details where fatigue damage is likely to occur. The actions specified by this AD are intended to prevent fatigue cracking that could compromise the structural integrity of these airplanes.
87-02-07: 87-02-07 BOEING: Amendment 39-5506. Applies to all Model 737-100 and 737-200 series airplanes, certificated in any category. To minimize the hazard of lower wing surface fuel tank access cover penetration due to impact from low energy engine debris, accomplish the following, unless already accomplished. \n\n\tA.\tWithin the next year after the effective date of this AD, replace the lower wing surface fuel tank access covers located immediately inboard and outboard of each engine (total of four per airplane), with covers having impact resistance equivalent to that of 2024-T3 aluminum 0.140-inch thick, as approved by the Manager, Seattle Aircraft Certification Office, FAA, Northwest Mountain Region. The replacement covers must also be fire resistant, as defined in the Federal Aviation Regulations, Part 1. \n\n\tB.\tAn alternate means of compliance or adjustment of the compliance time, which provides an acceptable level of safety, may be used when approved by the Manager, Seattle Aircraft Certification Office, FAA, Northwest Mountain Region. \n\n\tC.\tSpecial flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base for the accomplishment of the modifications required by this AD. \n\n\tThis amendment becomes effective February 9, 1987.
93-06-01: 93-06-01 BOEING: Amendment 39-8526. Docket 92-NM-148-AD. Supersedes AD 84-21-02 R1, Amendment 39-6430.\n\n\tApplicability: Model 747 series airplanes, as listed in Section 3.0 of Boeing Document No. D6-35022, "Supplemental Structural Inspection Document" (SSID), Revision D, dated February 1992, certificated in any category.\n\n\tCompliance: Required as indicated, unless accomplished previously.\n\n\tTo ensure the continuing structural integrity of the total Boeing Model 747 fleet, accomplish the following:\n\n\t(a)\tFor airplanes listed in Boeing Document No. D6-35022, Revision C, dated April 1989: Within 3 months after February 12, 1990 (the effective date of AD 84-21-02 R1, Amendment 39-6430), incorporate a revision into the FAA-approved maintenance inspection program which provides no less than the required Damage Tolerance Rating (DTR) for each Structural Significant Item (SSI) listed in Boeing Document No. D6-35022, Revision C, dated April 1989. (The required DTR value for eachSSI is listed in the document.) The revision to the maintenance program shall include and be implemented in accordance with the procedures in Sections 5.0 and 6.0 of the SSID.\n\n\t(b)\tFor airplanes listed in Boeing Document No. D6-35022, Revision D, dated February 1992: Within 12 months after the effective date of this AD, replace the revision of the FAA-approved maintenance inspection program required by paragraph (a) of this AD with a revision that provides no less than the required DTR for each SSI listed in Boeing Document No. D6-35022, Revision D, dated February 1992. (The required DTR value for each SSI is listed in the document.) The revision to the maintenance program shall include and be implemented in accordance with the procedures in Sections 5.0 and 6.0 of the SSID.\n\n\t(c)\tCracked structure must be repaired, prior to further flight, in accordance with an FAA-approved method.\n\n\t(d)\tAn alternative method of compliance or adjustment of the compliance time that providesan acceptable level of safety may be used if approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Seattle ACO.\n\n\tNOTE: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO.\n\n\t(e)\tSpecial flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate the airplane to a location where the requirements of this AD can be accomplished.\n\n\t(f)\tThe inspections shall be done in accordance with Boeing Document No. D6-35022, "Supplemental Structural Inspection Document (SSID)", Revision C, dated April 1989, and Boeing Document No. D6-35022, "Supplemental Structural Inspection Document (SSID)", Revision D, dated February 1992, comprised of Volumes I and II, which includes the following list of effective pages:\n\n\nPage Number\nRevision Ltr.\n\n\nList of Active Pages\nD\nPages 1 thru 21.1\n\n\n(NOTE: The issue date of Revision D is indicated only on the title page; no other page of the document is dated.) The incorporation by reference of Revision D was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51. The incorporation by reference of Revision C was approved previously by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51 as of February 12, 1990 (55 FR 1005, January 11, 1990). Copies may be obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124-2207. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.\n\n\t(g)\tThis amendment becomes effective on May 17, 1993.
2000-24-19: This amendment adopts a new airworthiness directive (AD), applicable to all Learjet Model 35, 35A, 36, and 36A series airplanes, that requires revision of the Airplane Flight Manual (AFM) to add procedures for donning the flightcrew oxygen masks when the cabin altitude warning horn is activated. This amendment is intended to prevent incapacitation of the flightcrew due to lack of oxygen and consequent loss of control of the airplane due to absence of AFM procedures for donning the flightcrew oxygen masks when the cabin altitude warning horn is activated.
94-01-10: 94-01-10 BOEING: Amendment 39-8792. Docket 92-NM-173-AD. Supersedes AD 91-20-09, Amendment 39-8043.\n \n\tApplicability: Model 757 series airplanes equipped with Pratt and Whitney PW2000 series engines, certificated in any category. \n\n\tCompliance: Required as indicated, unless accomplished previously. \n\n\tNOTE 1: Paragraphs (a) and (b) of this AD restate the requirements of AD 91-20-09, Amendment 39-8043, paragraphs (a) and (b). As allowed by the phrase, "unless accomplished previously," if the requirements of AD 91-20-09 have been accomplished previously, paragraphs (a) and (b) of this AD do not require those actions to be repeated. \n\n\tNOTE 2: Paragraph (c) of this AD restates the requirement for repetitive inspections contained in paragraph (d) of AD 91-20-09, Amendment 39-8043. Paragraph (c) of this AD requires that the first inspection required by this AD must be performed within the specified repetitive inspection interval after the last inspection performed in accordance with paragraph (d) of AD 91-20-09. \n\n\tTo prevent deployment of a thrust reverser in flight and subsequent reduced controllability of the airplane, accomplish the following: \n\n\t(a)\tWithin 14 days after September 16, 1991 (the effective date of AD 91-20-09, Amendment 39-8043), accomplish either paragraph (a)(1) or (a)(2) of this AD. \n\n\t\t(1)\tAccomplish both paragraphs (a)(1)(i) and (a)(1)(ii) of this AD: \n\t\t\t(i)\tInspect the thrust reverser Directional Control Valve (DCV) assemblies of both engines to determine the solenoid-driven pilot valve's part number, in accordance with Boeing Alert Service Bulletin 757-78A0027, dated September 9, 1991.\n \n\t\t\t\t(A)\tIf any DCV has a suspect pilot valve as specified in the service bulletin, prior to further flight, replace the DCV with a DCV that has a part number of a non-suspect solenoid-driven pilot valve, in accordance with the service bulletin. \n\n\t\t\t\t(B)\tIf a DCV has a non-suspect solenoid-driven pilot valve as specified in the service bulletin, that pilot valve does not need to be replaced. \n\n\t\t\t(ii)\tPerform all tests and inspections of the engine thrust reverser control and indication system on both engines in accordance with Boeing Service Bulletin 757- 78-0025, dated September 9, 1991. Prior to further flight, correct any discrepancy found in accordance with the service bulletin. \n\n\t\t(2)\tAccomplish paragraph (a)(1) of this AD on one engine's thrust reverser and deactivate the other engine's thrust reverser, in accordance with Section 78-31-1 of Boeing Document D630N002, "Boeing 757 Dispatch Deviation Guide," Revision 8, dated January 15, 1991.\n \n\t(b)\tWithin 24 days after September 16, 1991 (the effective date of AD 91-20-09, Amendment 39-8043), the requirements of paragraph (a)(1) of this AD must be accomplished on both engines' thrust reverser systems. \n\n\t(c)\tRepeat the tests and inspections specified in paragraph (a)(1)(ii) at intervals not to exceed 3,000 flight hours, and prior to further flight following any maintenance that disturbs the thrust reverser control system. Prior to further flight, correct any discrepancy found in accordance with Boeing Service Bulletin 757-78-0025, dated September 9, 1991. \n\n\t(d)\tWithin 5 years after the effective date of this AD, install an additional thrust reverser system locking feature (sync lock installation), in accordance with Boeing Service Bulletin 757-78-0028, Revision 1, dated October 29, 1992, or Revision 2, dated January 14, 1993. \n\n\t(e)\tWithin 1,000 hours time-in-service after installing the sync lock required by paragraph (d) of this AD (either in production or by retrofit), or within 1,000 hours time-in- service after the effective date of this AD, whichever occurs later; and thereafter at intervals not to exceed 1,000 hours time-in-service: Perform functional tests of the sync lock in accordance with the "Thrust Reverser Sync Lock Integrity Test" procedures specified below. If any discrepancy is found during any test, prior to further flight, correct it in accordance with procedures described in the Boeing 757 Maintenance Manual. \n\n\t\t"THRUST REVERSER SYNC LOCK INTEGRITY TEST \n\n1.\tGeneral \n\tA.\tUse this procedure to test the integrity of the thrust reverser sync locks. \n\n2.\tThrust Reverser Sync Lock Test \n\tA.\tPrepare for the Thrust Reverser Sync Lock Test. \n\n\t\t(1)\tOpen the AUTO SPEEDBRAKE circuit breaker on the overhead \t\t\t\tcircuit breaker panel, P11. \n\n\t\t(2)\tDo the steps that follow to supply power to the thrust reverser system: \n\t\t\t(a)\tMake sure the thrust levers are in the idle position. \n\n\t\t\tCAUTION:\tDO NOT EXTEND THE THRUST REVERSER \t\t\t\t\t\tWHILE THE CORE COWL PANELS ARE OPEN. \t\t\t\t\tDAMAGE TO THE THRUST REVERSER AND \t\t\t\t\t\tCORE COWL PANELS CAN OCCUR. \n\n\t\t\t(b)\tMake sure the thrust reverser halves are closed. \n\t\t\t(c)\tMake sure the core cowl panels are closed. \t\t\t\t\t(d)\tPut the EEC MAINT POWER switch or the EEC POWER L \t\t\t\tand EEC POWER R switches to the ALTN position. \n\n\t\t\t(e)\tFor the left engine: \n\n\t\t\t\t1)\tPut the EEC MAINT CHANNEL SEL L switch to the \n\t\t\t\t\tAUTO position. \n\t\t\t\t2)\tPut the L ENG fire switch to the NORM position. \n\n\t\t\t(f)\tFor the right engine: \n\n\t\t\t\t1)\tPut the EEC MAINT CHANNEL SEL R switch to the \n\t\t\t\t\tAUTO position. \n\t\t\t\t2)\tPut the R ENG fire switch to the NORM position. \n\n\t\t\t(g)\tMake sure the EICAS circuit breakers (6 locations) are \t\t\t\t\tclosed. \n\n\t\t\tWARNING:\tTHE THRUST REVERSER WILL AUTOMATICALLY \n\t\t\t\t\tRETRACT IF THE ELECTRICAL POWER TO THE \n\t\t\t\t\tEEC/THRUST REVERSER CONTROL SYSTEM IS \n\t\t\t\t\tTURNED OFF OR IF THE EEC MAINT POWER \n\t\t\t\t\tSWITCH IS MOVED TO THE NORM POSITION. \t\t\t\t\tTHE ACCIDENTAL OPERATION OF THE THRUST \n\t\t\t\t\tREVERSER CAN CAUSE INJURY TO PERSONS \t\t\t\t\tOR DAMAGE TO EQUIPMENT CAN OCCUR. \n\n\t\t\t(h)\tMake sure these circuit breakers on the main power \t\t\t\t\tdistribution panel, P6, are closed: \n\n\t\t\t\t1)\tFUEL COND CONT L \n\t\t\t\t2)\tFUEL COND CONT R \n\t\t\t\t3)\tT/L INTERLOCK L \n\t\t\t\t4)\tT/L INTERLOCK R \n\t\t\t\t5)\tLEFT T/R SYNC LOCK6)\tRIGHT T/R SYNC LOCK \n\t\t\t\t7)\tL ENG ELECTRONIC ENGINE CONTROL ALTN \t\t\t\t\tPWR \n\t\t\t\t\t(if installed) \n\t\t\t\t8)\tR ENG ELECTRONIC ENGINE CONTROL ALTN \t\t\t\t\tPWR \n\t\t\t\t\t(if installed) \n\n\t\t\t(i)\tMake sure these circuit breakers on the overhead circuit \n\t\t\t\tbreaker panel, P11, are closed: \n\n\t\t\t\t1)\tAIR/GND SYS 1 \n\t\t\t\t2)\tAIR/GND SYS 2 \n\t\t\t\t3)\tLANDING GEAR POS SYS 1 \n\t\t\t\t4)\tLANDING GEAR POS SYS 2 \n\n\t\t\t(j)\tFor the left engine, make sure these circuit breakers on the \t\t\t\tP11 panel are closed: \n\n\t\t\t\t1)\tLEFT ENGINE PDIU \n\t\t\t\t2)\tLEFT ENGINE THRUST REVERSER CONT/SCAV \n\t\t\t\t\tPRESS \n\t\t\t\t3)\tLEFT ENGINE ELECTRONIC ENGINE CONTROL \n\t\t\t\t\tALTN PWR (if installed) \n\t\t\t\t4)\tLEFT ENGINE THRUST REVERSER PRI CONT 5)\n\t\t\t\t\tLEFT ENGINE THRUST REVERSER SEC CONT \n\n\t\t\t(k)\tFor the right engine, make sure these circuit breakers on the \n\t\t\t\tP11 panel are closed: \n\n\t\t\t\t1)\tRIGHT ENGINE PDIU \n\t\t\t\t2)\tRIGHT ENGINE THRUST REVERSER CONT/SCAV \n\t\t\t\t\tPRESS \n\t\t\t\t3)\tRIGHT ENGINE ELECTRONIC ENGINE CONTROLALTN PWR (if installed) \n\t\t\t\t4)\tRIGHT ENGINE THRUST REVERSER PRI CONT \n\t\t\t\t5)\tRIGHT ENGINE THRUST REVERSER SEC CONT \n\n\t\t\t(l)\tSupply electrical power. \n\n\t\t\t(m)\tRemove the pressure from the left (right) hydraulic system. \n\n\tB.\tDo the Thrust Reverser Sync Lock Test. \n\n\t\t(1)\tMove and hold the manual unlock lever on the center actuator on both \t\t\tthrust reverser sleeves to the unlock position. \n\t\t(2)\tMake sure the thrust reverser sleeves did not move. \n\t\t(3)\tMove the left (right) reverser thrust lever up and rearward to the idle \n\t\t\tdetent position. \n\t\t(4)\tMake sure both thrust reverser sleeves move aft (approximately 0.15 \t\t\tto 0.25 inch). \n\t\t(5)\tRelease the manual unlock lever on the center actuators. \n\n\n\t\tWARNING:\tMAKE SURE ALL PERSONS AND EQUIPMENT ARE \t\t\tCLEAR OF THE AREA AROUND THE THRUST REVERSER. WHEN YOU \t\tAPPLY \tHYDRAULIC PRESSURE THE THRUST REVERSER WILL EXTEND \t\tAND CAN CAUSE INJURIES TO PERSONS OR DAMAGE TO EQUIPMENT. \n\n\t\t(6)\tPressurize the left (right) hydraulic system. \n\t\t(7)\tMake sure the thrust reverser extends. \n\t\t(8)\tMove the left (right) reverser thrust lever to the fully forward and down \n\t\t\tposition to retract the thrust reverser.\n \n\tC.\tPut the Airplane Back to its Usual Condition. \n\n\t\t(1)\tRemove hydraulic pressure. \n\t\t(2)\tClose the left and right fan cowls. \n\t\t(3)\tClose the AUTO SPEEDBRAKE circuit breaker on the P11 panel. \n\t\t(4)\tRemove electrical power if it is not necessary. \n\n\tD.\tRepeat the Thrust Reverser Sync Lock Test on the other engine." \n\n\t(f)\tInstallation of the sync lock, as required by paragraph (d) of this AD, constitutes terminating action for the requirements of paragraphs (a) through (c) of this AD. \n\n\t(g)\tAn alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Seattle ACO. \n\n\tNOTE 3: Approvals of alternative methods of compliance issued for AD 91-20-09 constitute valid approvals for compliance with the requirements of paragraphs (a) through (c) of this AD. \n\n\tNOTE 4: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO. \n\n\t(h)\tSpecial flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate the airplane to a location where the requirements of this AD can be accomplished. \n\n\t(i)\tThe actions shall be done in accordance with Boeing Alert Service Bulletin 757- 78A0027, dated September 9, 1991; Boeing Service Bulletin 757-78-0025, dated September 9, 1991; Boeing Document D630N002, "Boeing 757 Dispatch Deviation Guide," Revision 8, dated January 15, 1991; Boeing Service Bulletin 757-78-0028, Revision 1, dated October 29, 1992; andBoeing Service Bulletin 757-78-0028, Revision 2, dated January 14, 1993. The incorporation by reference of Boeing Alert Service Bulletin 757-78A0027, dated September 9, 1991; Boeing Service Bulletin 757-78-0025, dated September 9, 1991; Boeing Document D630N002, "Boeing 757 Dispatch Deviation Guide," Revision 8, dated January 15, 1991; was approved previously by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51 as of September 16, 1991 (56 FR 46725, September 16, 1991). The incorporation by reference of the remainder of the service documents listed above is approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51. Copies may be obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124-2207. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. \n\n\t(j)\tThis amendment becomes effective on March 3, 1994.