92-18-12 BOEING: Amendment 39-8357. Docket No. 91-NM-234-AD. Supersedes AD 91-18-08, Amendment 39-8011. \n\n\tApplicability: Model 747 series airplanes, equipped with brake part numbers (P/N) identified in paragraphs (a) and (b) of this AD, certificated in any category. \n\n\tCompliance required as indicated, unless previously accomplished. \n\n\tTo prevent loss of main landing gear braking effectiveness, accomplish the following: \n\n\t(a)\tWithin 180 days after November 12, 1991 (the effective date of Amendment 39-8011, AD 91-18-08), incorporate the maximum brake wear limits, shown below, into the FAA-approved maintenance inspection program: \n\n\nBrake Mfr.\t\t\t\nBrake P/N\nBoeing P/N\nMaximum Wear Limit \nBendix\n2603703-13\n60B10014-9\n1.55 inches \nBendix\n2603703-14\n60B10014-11\n1.55 inches \nBendix\n2605662-1\n60B10014-15\n2.50 inches\nBendix\n2605662-3\n60B10014-23\n2.70 inches \nBFGoodrich\n2-1515-1\n60B10062-11\n2.00 inches \nBFGoodrich\n2-1515-2\n60B10062-12\n2.00 inches(b)\tWithin 180 days after the effective date of this AD, accomplish the requirements specified in paragraph (b)(1), (b)(2), (b)(3), (b)(4), (b)(5), or (b)(6) of this AD, as applicable: \n\n\t\t(1)\tFor airplanes equipped with Bendix Part Numbers (P/N) 2602012-2, -3, -4, and -5, (Boeing P/N 60B00150-5, -6, -8, and -12): \n\n\t\t\t(i)\tInspect each brake to ensure it is not worn more than 1.75 inches. Any brake worn more than this limit must be replaced, prior to further flight, with a brake within this limit; or with a Bendix Brake P/N 2602012-30, -40, or -50, (Boeing P/N 60B00150-21, -22, and -23), as applicable, built in accordance with Bendix Service Bulletin 2602012-32-001, Revision 2, dated October 10, 1991. \n\n\t\t\t(ii)\tAdd Bendix Brake P/N's 2602012-30, -40, and -50 to the FAA-approved Airplane Flight Manual (AFM), Section 4, "Maximum Brake Energy Limit Speed," Category "B", and remove Bendix brake P/N's 2602012-2, -3, -4, and -5 from the AFM. \n\n\t\t\t(iii)\tIntermix of the P/N 2602012-2, -3, -4, and -5 brakes with the P/N 2602012-30, -40 and -50 brakes is allowed for 360 days after the effective date of this AD. Delay removal of the P/N 2602012-2, -3, -4, and -5 brakes from the AFM, as required by paragraph (b)(1)(ii) of this AD, until intermix is ended. \n\n\t\t\t(iv)\tChange all references of Bendix Brake P/N's 2602012-2, -3, -4, and -5 to Category "B" on the Maximum Brake Energy Chart in Section 4 of the AFM. \n\n\t\t\t(v)\tIncorporate a 1.75-inch maximum allowable brake wear limit for Bendix Brake P/N's 2602012-30, -40, and -50 into the FAA-approved maintenance inspection program. \n\n\t\t(2)\tFor airplanes equipped with Bendix Brake P/N's 2601902-1, -2, and -5, (Boeing P/N's 60B00150-4, -9, and -13): Incorporate a 2.38-inch maximum allowable brake wear limit into the FAA-approved maintenance inspection program. \n\n\t\t(3)\tFor airplanes equipped with Bendix Brake P/N's 2601902-3, -4, and -6, (Boeing P/N's 60B00150-10, -11, and -14): \n\n\t\t\t(i)\tInspect each brake to ensure it is not worn more than 1.73 inches. Any brake worn more than this limit must be replaced, prior to further flight, with a brake within this limit; or with a Bendix Brake P/N 2601902-30, -40, or -60, (Boeing P/N's 60B00150-24, -25, and -26), as applicable, built in accordance with Bendix Service Bulletin 2601902-32-001, Revision 2, dated October 10, 1991. \n\n\t\t\t(ii)\tAdd Bendix Brake P/N's 2601902-30, -40, and -60 to the AFM, Section 4, "Maximum Brake Energy Limit Speed," Category "C". \n\n\t\t\t(iii)\tIntermix of the P/N 2601902-3, -4, and -6 brakes with the P/N 2601902-30, -40, and -60 brakes is allowed for 360 days after the effective date of this AD when a 1.73-inch maximum allowable brake wear limit removal criteria is used for these brakes. \n\n\t\t\t(iv)\tMove Bendix Brake P/N's 2601902-3, -4, and -6 from Category "C" to Category "B" in the AFM, Section 4, "Maximum Brake Energy Limit Speed." If intermixing is used, delay movement of these brakes to Category "B" until intermixing isended. \n\n\t\t\t(v)\tChange all references of Bendix P/N's 2601902-3, -4, and -6 to Category "C" on the Maximum Brake Energy Chart in Section 4 of the AFM. \n\n\t\t\t(vi)\tIncorporate a 2.38-inch maximum allowable brake wear limit for Bendix Brake P/N's 2601902-3, -4, and -6, and a 1.73-inch maximum allowable brake wear limit for P/N's 2601902-30, -40, and -60, into the FAA-approved maintenance inspection program. \n\n\t\t(4)\tFor airplanes equipped with Bendix Brake P/N 2605662-2, (Boeing P/N 60B10014-14): \n\n\t\t\t(i)\tInspect each brake to ensure that it is not worn more than 1.73 inches. Any brake worn more than this limit must be replaced, prior to further flight, with a brake within this limit; or with Bendix Brake P/N 2605662-20, (Boeing P/N 60B10014-30), built in accordance with Bendix Service Bulletin 2605662-32-028, Revision 2, dated October 10, 1991. \n\n\t\t\t(ii)\tAdd Bendix Brake P/N 2605662-20 to the AFM, Section 4, "Maximum Brake Energy Limit Speed," Category "C". \n\n\t\t\t(iii)\tIntermixof the P/N 2605662-2 brakes with the P/N 2605662-20 brakes is allowed for 360 days after the effective date of this AD when a 1.73-inch maximum allowable wear limit removal criteria is used for these brakes. \n\n\t\t\t(iv)\tMove Bendix Brake P/N 2605662-2 from Category "C" to Category "B" in the AFM, Section 4, "Maximum Brake Energy Limit Speed." If intermixing is used, delay movement of these brakes to Category "B" until intermix is ended. \n\n\t\t\t(v)\tChange all references of Bendix P/N 2605662-2 to Category "C" on the Maximum Brake Energy Chart in Section 4 of the AFM. \n\n\t\t\t(vi)\tIncorporate a 2.38-inch maximum allowable brake wear limit for Bendix Brake P/N 2605662-2, and a 1.73-inch maximum allowable brake wear limit for P/N 2605662-20, into the FAA-approved maintenance inspection program. \n\n\t\t(5)\tFor airplanes equipped with Bendix Brake P/N 2605155-1, (Boeing P/N 60B10014-10): \n\n\t\t\t(i)\tInspect each brake to ensure that it is not worn more than 2.50 inches. Any brake worn more than this limit must be replaced, prior to further flight, with a brake within this limit; or with Bendix Brake P/N 2605155-2, (Boeing P/N 60B10014-31), built in accordance with Bendix Service Bulletin 2605155-32-001, Revision 2, dated October 10, 1991. \n\n\t\t\t(ii)\tAdd Bendix Brake P/N 2605155-2 to the Airplane Flight Manual (AFM), Section 4, "Maximum Brake Energy Limit Speed," Category "C". \n\n\t\t\t(iii)\tIntermix of the P/N 2605155-1 brakes with the P/N 2605155-2 brakes is allowed for 360 days after the effective date of this AD when a 2.50-inch maximum allowable wear limit removal criteria is used for these brakes. \n\n\t\t\t(iv)\tMove Bendix Brake P/N 2605155-1 from Category "C" to Category "B" in the AFM, Section 4, "Maximum Brake Energy Limit Speed." If intermixing is used, delay movement of this brake to Category "B" until intermixing is ended. \n\n\t\t\t(v)\tChange all references of Bendix P/N 2605155-1 to Category "C" on the Maximum Brake Energy Chart in Section 4 of the AFM. \n\n\t\t\t(vi)Incorporate a 3.20-inch maximum allowable brake wear limit for Bendix Brake P/N 2605155-1, and a 2.50-inch maximum allowable brake wear limit for P/N 2605155-2, into the FAA-approved maintenance inspection program. \n\n\t\t(6)\tFor airplanes equipped with Bendix Brake P/N 2605392-1, (Boeing P/N 60B10035-2): Incorporate a 1.90-inch maximum allowable brake wear limit into the FAA-approved maintenance inspection program. \n\n\t(c)\tAn alternative method 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 (ACO), FAA, Transport Airplane Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may concur or comment 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.(d)\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\t(e)\tBrakes shall be built in accordance with Bendix Service Bulletin 2601902-32-001, Revision 2, dated October 10, 1991; Bendix Service Bulletin 2602012-32-001, Revision 2, dated October 10, 1991; Bendix Service Bulletin 2605155-32-001, Revision 2, dated October 10, 1991; or Bendix Service Bulletin 2605662-32-028, Revision 2, dated October 10, 1991; as applicable. 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 Allied-Signal Aerospace Company, Bendix Wheels and Brakes Division, South Bend, Indiana 46628. 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(f)\tThis amendment becomes effective on November 17, 1992.