AD 2000-15-04 Airworthiness Directives; Boeing Model 747-200 and -300 Series Airplanes Equipped with General Electric CF6-80C2 Series Engines

Models named: 747-200, -300 series, CF6-80C2 series. Read the applicability below — it usually turns on serial or part numbers too.

Model 747-200 and -300 series airplanes equipped with General Electric Model CF6-80C2 series engines with Power Management Control engine controls, 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 (h)(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.

Required as indicated, unless accomplished previously. To 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: RESTATEMENT OF THE ORIGINAL REQUIREMENTS OF AD 95-06-01: Repetitive Tests and Inspections (a) Within 90 days after April 13, 1995 (the effective date of AD 95-06-01, amendment 39-9171), perform tests of the position switch module and the cone brake of the center drive unit (CDU) on each thrust reverser, and perform an inspection to detect damage to the bullnose seal on the translating sleeve on each thrust reverser, in accordance with paragraphs III.A. through III.C. of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-78A2130, dated May 26, 1994. Repeat the tests and inspection thereafter at intervals not to exceed 1,000 hours time-in-service until the functional test required by paragraph (d) of this AD is accomplished. (b) Within 9 months after April 13, 1995, perform inspections and functional tests of the thrust reverser control and indication system in accordance with paragraphs III.D. through III.F., III.H., and III.I. of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-78A2130, dated May 26, 1994. Repeat these inspections and functional tests thereafter at intervals not to exceed 18 months. Corrective Action (c) If any of the inspections and/or functional tests required by paragraphs (a) and (b) of this AD cannot be successfully performed, or if any discrepancy is found during those inspections and/or functional tests, accomplish either paragraph (c)(1) or (c)(2) of this AD. (1) Prior to further flight, correct the discrepancy found, in accordance with Boeing Alert Service Bulletin 747-78A2130, dated May 26, 1994. Or (2) The airplane may be operated in accordance with the provisions and limitations specified in an operator's FAA-approved Minimum Equipment List (MEL), provided that no more than one thrust reverser on the airplane is inoperative. RESTATEMENT OF REQUIREMENTS OF AD 99-15-08: Repetitive Tests/Terminating Action (d) Within 1,000 hours time-in-service after the most recent test of the CDU cone brake performed in accordance with paragraph (a) of this AD, or within 650 hours time-in-service after August 25, 1999 (the effective date of AD 99-15-08, amendment 39-11227), whichever occurs first: Perform a functional test to detect discrepancies of the CDU cone brake on each thrust reverser, in accordance with Boeing Service Bulletin 747-78A2166, Revision 1, dated October 9, 1997, or paragraph III.B. of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-78A2130, dated May 26, 1994. Repeat the functional test thereafter at the interval specified in paragraph (d)(1) or (d)(2) of this AD, as applicable. Accomplishment of such functional test constitutes terminating action for the repetitive test of the CDU cone brake required by paragraph (a) of this AD; the position switch module tests and the bullnose seal inspections continue to be required as specified in paragraph (a) of this AD. (1) For airplanes equipped with thrust reversers NOT modified in accordance with Boeing Service Bulletin 747-78-2144, Revision 1, dated April 11, 1996: Repeat the functional test at intervals not to exceed 650 hours time-in-service. (2) For airplanes equipped with thrust reversers modified in accordance with Boeing Service Bulletin 747-78-2144, Revision 1, dated April 11, 1996: Repeat the functional test at intervals not to exceed 1,000 hours time-in-service. Corrective Action (e) If any functional test required by paragraph (d) of this AD cannot be successfully performed, or if any discrepancy is found during any functional test required by paragraph (d) of this AD, accomplish either paragraph (e)(1) or (e)(2) of this AD. (1) Prior to further flight, correct the discrepancy found, in accordance with Boeing Service Bulletin 747-78A2166, Revision 1, dated October 9, 1997, or paragraph III.B. of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-78A2130, dated May 26, 1994. Or (2) The airplane may be operated in accordance with the provisions and limitations specified in the operator's FAA-approved MEL, provided that no more than one thrust reverser on the airplane is inoperative. NEW REQUIREMENTS OF THIS AD: Terminating Action (f) Accomplish the requirements of paragraphs (f)(1) and (f)(2) of this AD at the times specified in those paragraphs. Accomplishment of the actions required by paragraph (f)(1) of this AD constitutes terminating action for the requirements of paragraphs (a), (b), (d), and (e) of this AD. (1) Within 36 months after the effective date of this AD, accomplish the requirements of paragraphs (f)(1)(i) and (f)(1)(ii) of this AD. (i) Install an actuation system lock bracket and fastening hardware to each thrust reverser in accordance with the Accomplishment Instructions of Lockheed Martin Service Bulletin 78-1007, Revision 1, dated March 18, 1997, or Middle River Aircraft Systems Service Bulletin 78-1007, Revision 2, dated March 10, 1998. (ii) Install an actuation system lock (also called an electro-mechanical lock or electro-mechanical brake) on each thrust reverser in accordance with the Accomplishment Instructions of Lockheed Martin Service Bulletin 78-1020, Revision 2, dated March 20, 1997, or Middle River Aircraft Systems Service Bulletin 78-1020, Revision 3, dated March 16, 1998. (2) Prior to or concurrent with the accomplishment of the requirements of paragraph (f)(1)(ii) of this AD, perform the thrust reverser wiring modifications of the wings, strut, and fuselage, in accordance with the Accomplishment Instructions of Boeing Service Bulletin 747-78-2144, Revision 1, dated April 11, 1996. Repetitive Tests (g) Within 1,000 hours time-in-service after accomplishment of paragraph (f) of this AD, or within 1,000 hours time-in-service after the effective date of this AD, whichever occurs later: Perform a functional test to detect discrepancies of the CDU cone brake and actuation system lock on each thrust reverser, in accordance with Appendix 1 of this AD. Prior to further flight, correct any discrepancy detected and repeat the functional test of that repair, in accordance with the procedures described in the Boeing 747 Maintenance Manual. Repeat the functional tests thereafter at intervals not to exceed 1,000 hours time-in-service. Alternative Methods of Compliance (h)(1) 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, 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. (2) Alternative methods of compliance, approved previously in accordance with AD 99-15-08, amendment 39-11227, are approved as alternative methods of compliance with the corresponding requirements specified in this AD. Note 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO. Special Flight Permits (i) 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. Incorporation by Reference (j) Except as provided by paragraphs (c)(2), (e)(2), and (g) of this AD, the actions shall be done in accordance with Boeing Alert Service Bulletin 747-78A2130, dated May 26, 1994; Boeing Service Bulletin 747-78A2166, Revision 1, dated October 9, 1997; Lockheed Martin Service Bulletin 78-1007, Revision 1, dated March 18, 1997; Middle River Aircraft Systems Service Bulletin 78-1007, Revision 2, dated March 10, 1998; Lockheed Martin Service Bulletin 78-1020, Revision 2, dated March 20, 1997; Middle River Aircraft Systems Service Bulletin 78-1020, Revision 3, dated March 16, 1998; or Boeing Service Bulletin 747-78-2144, Revision 1, dated April 11, 1996; as applicable. (1) The incorporation by reference of Lockheed Martin Service Bulletin 78-1007, Revision 1, dated March 18, 1997; Middle River Aircraft Systems Service Bulletin 78-1007, Revision 2, dated March 10, 1998; Lockheed Martin Service Bulletin 78-1020, Revision 2, dated March 20, 1997; Middle River Aircraft Systems Service Bulletin 78-1020, Revision 3, dated March 16, 1998; and Boeing Service Bulletin 747-78-2144, Revision 1, dated April 11, 1996; is approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Lockheed Martin Service Bulletin 78-1007, Revision 1, dated March 18, 1997, contains the following list of effective pages:   Page No. Revision level shown on page Date shown on page 1, 3, 4, 22-28 1 March 18, 1997. 2, 5-21 Original August 30, 1997. Lockheed Martin Service Bulletin 78-1020, Revision 2, dated March 20, 1997, contains the following list of effective pages:   Page No. Revision level shown on page Date shown on page 1-5, 8, 12, 13, 15, 19-21, 23-36 2 March 20, 1997. 6, 7, 9-11, 14, 16-18, 22, 37 1 January 17, 1996. (2) The incorporation by reference of Boeing Service Bulletin 747-78A2166, Revision 1, dated October 9, 1997, was approved previously by the Director of the Federal Register as of August 25, 1999 (64 FR 39003, July 21, 1999). (3) The incorporation by reference of Boeing Alert Service Bulletin 747-78A2130, dated May 26, 1994, was approved previously by the Director of the Federal Register as of April 13, 1995 (60 FR 13623, March 14, 1995). (4) 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. Effective Date (k) This amendment becomes effective on September 6, 2000. Appendix 1—Thrust Reverser Electro-Mechanical Brake and CDU Cone Brake Test 1. General A. This procedure contains steps to do two checks: (1) A check of the holding torque of the electro-mechanical brake. (2) A check of the holding torque of the CDU cone brake. 2. Electro-Mechanical Brake and CDU Cone Brake Torque Check A. Prepare to do the checks: (1) Open the fan cowl panels. B. Do a check of the torque of the electro-mechanical brake: (1) Do a check of the electro-mechanical brake holding torque: (a) Make sure the thrust reverser translating cowl is extended at least one inch. (b) Make sure the CDU lock handle is released. (c) Pull down on the manual release handle on the electro-mechanical brake until the handle fully engages the retaining clip. Note: This will lock the electro-mechanical brake. (d) With 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. Note: You will need a 24-inch extension to provide adequate clearance for the torque wrench. (e) Apply 90 pound-inches of torque to the system. (i) The electro-mechanical brake system is working correctly if the torque is reached before you turn the wrench 450 degrees (1 1/4 turns). (ii) If 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. (iii) If you do not get 90 pound-inches of torque, you must replace the electro-mechanical brake. (f) Release the torque by turning the wrench in the opposite direction until you read zero pound-inches. (i) If 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. (2) Fully retract the thrust reverser. C. Do a check of the torque of the CDU cone brake: (1) Pull up on the manual release handle to unlock the electro-mechanical brake. (2) Pull the manual brake release lever on the CDU to release the cone brake. Note: This will release the pre-load tension that may occur during a stow cycle. (3) Return the manual brake release lever to the locked position to engage the cone brake. (4) Remove the two bolts that hold the lockout plate to the CDU and remove the lockout plate. (5) Install a 1/4 -inch drive and a dial type torque wrench into the CDU drive pad. Caution: Do not use more than 100 pound-inches of torque when you do this check. Excessive torque will damage the CDU. (6) Turn the torque wrench to try to manually extend the translating cowl until you get at lease 15-pound inches. Note: The 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. (a) If the torque is less than 15-pound-inches, you must replace the CDU. D. Return the airplane to its usual condition: (1) Re-install the lockout plate. (2) Fully retract the thrust reverser (unless already accomplished). (3) Pull down on the manual release handle on the electro-mechanical brake until the handle fully engages the retaining clip (unless already accomplished). Note: This will lock the electro-mechanical brake. (4) Close the fan cowl panels. Issued in Renton, Washington, on July 18, 2000. Donald L. Riggin, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 00-18661 Filed 8-1-00; 8:45 am] BILLING CODE 4910-13-U