2000-09-04 BOEING: Amendment 39-11712. Docket 2000-NM-94-AD. Supersedes AD 2000-02-20, Amendment 39-11538. \n\n\tApplicability: Model 767 series airplanes equipped with General Electric Model CF6-80C2 series engines, certificated in any category. \n\n\tNOTE 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 (i)(1) 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. \n\n\tTo ensure the integrity of the fail safe features of the thrust reverser system by preventing possible failure modes in the thrust reverser control system that can result in inadvertent deployment of a thrust reverser during flight, accomplish the following: \n\nRepetitive Tests, Inspections, and Adjustments \n\n\t(a)\tWithin 30 days after August 18, 1995 (the effective date of AD 95-13-12 R1, amendment 39-9528), perform tests, inspections, and adjustments of the thrust reverser system in accordance with Boeing Service Bulletin 767-78-0047, Revision 3, dated July 28, 1994. \n\n\t\t(1)\tExcept as provided by paragraph (a)(2) of this AD, repeat all tests and inspections thereafter at intervals not to exceed 3,000 flight hours until the modification required by paragraph (c) of this AD is accomplished. \n\n\t\t(2)\tRepeat the check of the grounding wire for the Directional Pilot Valve (DPV) of the thrust reverser in accordance with the service bulletin at intervals not to exceed 1,500 flight hours, and whenever maintenance action is taken that would disturb the DPV grounding circuit, until the modification required by paragraph (c) of this AD is accomplished. \n\nRepair \n\n\t(b)\tIf any of the tests and/or inspections required by paragraph (a) of this AD cannot be successfully performed, or if those tests and/or inspections result in findings that are unacceptable in accordance with Boeing Service Bulletin 767-78-0047, Revision 3, dated July 28, 1994; accomplish paragraphs (b)(1) and (b)(2) of this AD. \n\n\t\t(1)\tPrior to further flight, deactivate the associated thrust reverser in accordance with Section 78-31-1 of Boeing Document D630T002, "Boeing 767 Dispatch Deviation Guide," Revision 9, dated May 1, 1991; or Revision 10, dated September 1, 1992. After August 18, 1995, this action shall be accomplished only in accordance with Revision 10 of the Boeing document. No more than one reverser on any airplane may be deactivated under the provisions of this paragraph. \n\n\t\t(2)\tWithin 10 days after deactivation of any thrust reverser in accordance with this paragraph, the thrust reverser must be repaired in accordance with Boeing Service Bulletin 767-78-0047, Revision 3, dated July 28, 1994. Additionally, the tests and/or inspections required by paragraph (a) of this AD must be successfully accomplished; once this is accomplished, the thrust reverser must then be reactivated. \n\nModification \n\n\t(c)\tFor airplanes having line numbers 1 through 474 inclusive: Within 3 years after August 18, 1995, install a third locking system on the left- and right-hand engine thrust reversers in accordance with Boeing Service Bulletin 767-78-0063, Revision 2, dated April 28, 1994. \n\n\tNOTE 2: Model 767 series airplanes equipped with General Electric Model CF6-80C2 series engines and having line numbers 475 and subsequent, on which Production Revision Record (PRR) B11481-70 (which installs a third locking system on the left- and right-hand engine thrust reversers) has been incorporated, need NOT be modified in accordance with Boeing Service Bulletin 767-78-0063, Revision 2. \n\n\tNOTE 3: Boeing Service Bulletin 767-78-0063, references General Electric (GE) Service Bulletin 78-135 as an additional source of service information for accomplishment of the third locking system on the thrust reversers. However, the Boeing service bulletin does not specify the appropriate revision level, and the GE service bulletin has a new Lockheed Martin title for the same service bulletin: Lockheed Martin Service Bulletin 78-135, Revision 4, dated September 30, 1996. The appropriate revision level for the GE Service Bulletin is Revision 3, dated August 2, 1994. The GE and Lockheed Martin service bulletins are identical, and either may be used for accomplishment of the action described previously. \n\n\tNOTE 4: The actions specified in Lockheed Martin Service Bulletin 78-1007, Revision 1, dated March 18, 1997; and Lockheed Martin Service Bulletin 78-1020, Revision 2, dated March 20, 1997; may be accomplished simultaneously in conjunction with Boeing Service Bulletin 767-78-0063 for accomplishment of the installation of the thrust reverser bracket and the thrust reverser lock. (Accomplishment of these two service bulletins together achieves the same results as Lockheed Martin Service Bulletin 78-135, Revision 4, and is acceptable for compliance with Boeing Service Bulletin 767-78-0063.) \n\nRepetitive Tests and Checks \n\n\t(d)\tPerform a functional test to detect discrepancies of the cone brake of the center drive unit (CDU) on each thrust reverser, as specified in paragraph (d)(1) or (d)(2) of this AD, as applicable. \n\n\t\t(1)\tFor airplanes on which the modification required by paragraph (c) of this AD or a production equivalent has NOT been accomplished: Within 650 flight hours after the effective date of this AD, perform the test in accordance with Boeing Service Bulletin 767-78A0081, Revision 1, dated October 9, 1997. \n\n\t\t(2)\tFor airplanes on which the modification required by paragraph (c) of this AD or a production equivalent has been accomplished: Perform the test in accordance with Appendix 1 (including Figure 1), sections 1.A.(2), 2.A., 2.C., and 2.D; of this AD. Accomplish the test at the time specified in paragraph (d)(2)(i) or (d)(2)(ii) of this AD, as applicable. \n\n\t\t\t(i)\tFor airplanes on which the test required by paragraph (d) of AD 95-13-12 R1 HAS been accomplished prior to the effective date of this AD: Accomplish the functional test within 1,000 flight hours after the most recent test of the CDU cone brake performed in accordance with paragraph (d) of AD 95-13-12 R1, or within 650 flight hours after the effective date of this AD, whichever occurs later. \n\n\t\t\t(ii)\tFor airplanes on which the test required by paragraph (d) of AD 95-13-12 R1 has NOT been accomplished prior to the effective date of this AD: Accomplish the functional testwithin 1,000 flight hours since the date of manufacture, or within 650 flight hours after the effective date of this AD, whichever occurs later. \n\n\t(e)\tRepeat the functional test of the CDU cone brake specified in paragraph (d) of this AD at the time specified in paragraph (e)(1) or (e)(2) of this AD, as applicable. \n\n\t\t(1)\tFor Model 767 series airplanes, line numbers up to and including 474, equipped with thrust reversers that have not been modified in accordance with Boeing Service Bulletin 767-78-0063: Repeat the functional test of the CDU cone brake thereafter at intervals not to exceed 650 flight hours. \n\n\t\t(2)\tFor Model 767 series airplanes, line numbers 475 and subsequent; and Model 767 series airplanes equipped with thrust reversers that have been modified in accordance with Boeing Service Bulletin 767-78-0063, or a production equivalent: Repeat the functional test of the CDU cone brake thereafter at intervals not to exceed 1,000 flight hours. \n\n\t(f)\tWithin 1,000 flight hours after accomplishing the modification required by paragraph (c) of this AD or after the equivalent modification (Production Revision Record B11481-70) is incorporated in production, or within 1,000 flight hours after March 9, 2000, whichever occurs later: Perform operational checks of the electro-mechanical brake in accordance with Appendix 1 (including Figure 1); sections 1.A.(1), 2.A., 2.B., and 2.D; of this AD. Repeat the operational checks thereafter at intervals not to exceed 1,000 flight hours. \n\nRepair \n\n\t(g)\tIf any functional test or operational check required by paragraph (d), (e), or (f) of this AD cannot be successfully performed, prior to further flight, repair in accordance with Boeing Service Bulletin 767-78A0081, Revision 1, dated October 9, 1997; or Appendix 1, section 2.B. and 2.C., of this AD; as applicable; and repeat the applicable test or check until successfully accomplished. \n\nTerminating Action \n\n\t(h)\tAccomplishment of the modification required by paragraph (c) or installation of an equivalent modification (Production Revision Record B11481-70) in production, and accomplishment of the periodic functional tests and operational checks required by paragraphs (d), (e), and (f) of this AD, constitutes terminating action for the tests, inspections, and adjustments required by paragraph (a) of this AD. \n\nAlternative Methods of Compliance \n\n\t(i)\t(1)\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\t\t(2)\tAlternative methods of compliance, approved previously in accordance with AD 95-13-12, amendment 39-9292, are approved as alternative methods of compliance with this AD.NOTE 5: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO. \n\nSpecial Flight Permits \n\n\t(j)\tSpecial 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. \n\nIncorporation by Reference \n\n\t(k)\tExcept as provided by paragraphs (b)(1), (d)(2), and (f) of this AD, the actions shall be done in accordance with Boeing Service Bulletin 767-78-0047, Revision 3, dated July 28, 1994; Boeing Service Bulletin 767-78-0063, Revision 2, dated April 28, 1994; and Boeing Service Bulletin 767-78A0081, Revision 1, dated October 9, 1997; as applicable. \n\n\t\t(1)\tThe incorporation by reference of Boeing Service Bulletin 767-78A0081, Revision 1, dated October 9, 1997, was previously approved by the Director of the Federal Register, as ofMarch 9, 2000 (65 FR 5229, February 3, 2000). \n\n\t\t(2)\tThe incorporation by reference of Boeing Service Bulletin 767-78-0047, Revision 3, dated July 28, 1994; and Boeing Service Bulletin 767-78-0063, Revision 2, dated April 28, 1994; was previously approved by the Director of the Federal Register, as of August 18, 1995 (60 FR 36976, July 19, 1995). \n\n\t\t(3)\tCopies 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(l)\tThis amendment becomes effective on May 19, 2000. \n\n\nAPPENDIX 1.\nTHRUST REVERSER ELECTRO-MECHANICAL BRAKE AND CDU CONE BRAKE TEST\n\n1.\tGeneral\n\n\tA.\tThis procedure contains steps to do two checks:\n\n\t\t(1)\tA check of the holding torque of the electro-mechanical brake.\n\n\t\t(2)\tA check of the holdingtorque of the CDU cone brake.\n\n2.\tElectro-mechanical Brake and CDU Cone Brake Torque Check (Fig. 1)\n\n\tA.\tPrepare to do the checks:\n\n\t\t(1)\tOpen the fan cowl panels.\n\n\tB.\tDo a check of the torque of the electro-mechanical brake:\n\n\t\t(1)\tDo a check of the running torque of the thrust reverser system:\n\n\t\t\t(a)\tManually extend the thrust reverser six inches and measure the running torque.\n\n\t\t\t\t1)\tMake sure the torque is less than 10 pound-inches.\n\n\t\t(2)\tDo a check of the electro-mechanical brake holding torque:\n\n\t\t\t(a)\tMake sure the thrust reverser translating cowl is extended at least one inch.\n\n\t\t\t(b)\tMake sure the CDU lock handle is released.\n\n\t\t\t(c)\tPull down on the manual release handle on the electro-mechanical brake until the handle fully engages the retaining clip.\n\nNOTE:\tThis will lock the electro-mechanical brake.\n\n\t\t\t(d)\tWith the manual drive lockout cover removed from the CDU, install a 1/4-inch extension tool and dial-type torque wrench into the drive pad.\n\nNOTE:\tYou will need a 24-inch extension to provide adequate clearance for the torque wrench.\n\n\t\t\t(e)\tApply 90 pound-inches of torque to the system.\n\n\t\t\t\t1)\tThe electro-mechanical brake system is working correctly if the torque is reached before you turn the wrench 450 degrees (1-1/4 turns).\n\n\t\t\t\t2)\tIf the flexshaft turns more than 450 degrees before you reach the specified torque, you must replace the long flexshaft between the CDU and the upper angle gearbox.\n\n\t\t\t\t3)\tIf you do not get 90 pound-inches of torque, you must replace the electro-mechanical brake.\n\n\t\t\t(f)\tRelease the torque by turning the wrench in the opposite \t\t\t\tdirection until you read zero pound-inches.\n\n\t\t\t\t1)\tIf the wrench does not return to within 30 degrees of initial starting point, you must replace the long flexshaft between the CDU and upper angle gearbox.\n\n\t\t(3)\tFully retract the thrust reverser.\n\n\tC.\tDo a check of the CDU cone brake:\n\n\t\t(1)\tPull up on the manual release handle to unlockthe electro-mechanical brake.\n\n\t\t(2)\tPull the manual brake release lever on the CDU to release the cone brake.\n\nNOTE:\tThis will release the pre-load tension that may occur during a stow cycle.\n\n\t\t(3)\tReturn the manual brake release lever to the locked position to engage the cone brake.\n\n\t\t(4)\tRemove the two bolts that hold the lockout plate to the CDU and remove the lockout plate.\n\n\t\t(5)\tInstall a 1/4-inch drive and a dial type torque wrench into the CDU drive pad.\n\nCAUTION:\tDO NOT USE MORE THAN 100 POUND-INCHES OF TORQUE WHEN YOU DO THIS CHECK. EXCESSIVE TORQUE WILL DAMAGE THE CDU.\n\n\t\t(6)\tTurn the torque wrench to try to manually extend the translating cowl until you get at lease 15-pound inches.\n\nNOTE:\tThe cone brake prevents movement in the extend direction only. If you try to measure the holding torque in the retract direction, you will get a false reading.\n\n\t\t\t(a)\tIf the torque is less than 15-pound-inches, you must replace the CDU.\n\n\tD.\tReturn the airplane toits usual condition:\n\n\t\t(1)\tFully retract the thrust reverser (unless already accomplished).\n\n\t\t(2)\tPull down on the manual release handle on the electro-mechanical brake until the handle fully engages the retaining clip (unless already accomplished).\n\nNOTE:\tThis will lock the electro-mechanical brake.\n\n\t\t(3)\tClose the fan cowl panels.