79-05-01 MCDONNELL DOUGLAS: Amendment 39-3421. Applies to DC-10-10, -10F, -30, -30F and -40 series airplanes certificated in all categories. \n\n\tCompliance is required as indicated. \n\n\tTo reduce the probability of an autopilot "land" mode failure that could cause automatic landing system performance outside the certification limits, accomplish the following, unless already accomplished: \n\n\ta.\tWithin the next 100 hours' time in service from the effective date of this AD, on airplanes with 33,000 or more hours time in service on wire bundles serviced by receptacles R5/P1-226, R5/P1-267, R5/P1-281 or R5/P1-282: \n\n\t\t1.\tDeactivate the autopilot "land" mode in accordance with paragraph (d) of this AD; or \n\n\t\t2.\tReplace wire bundles with like serviceable parts and comply with the inspection schedule of paragraph (b) of this AD; or \n\n\t\t3.\tReplace wire bundles per McDonnell Douglas DC-10 Service Bulletin 24-99, dated September 29, 1978. This option terminates the need for further testing as required by this AD. \n\n\tNOTE: Service Bulletin A24-99, dated June 19, 1978, or Service Bulletin 24-99, dated September 29, 1978, are the only versions of the service bulletins suitable for compliance with paragraphs (a) and (b) of this AD. \n\n\tb.\tWithin the total time in service on the wire bundles identified in paragraph (a) and as specified in the following table: \n\n\nTotal Hours' Time in Service\n On Wire Bundles\nInitial Testing\n Repetitive Testing \n\n\n\n10,000-12,999\nWithin 3,000 additional hours' time in service after the effective date of this AD\t\n3,000 hours' time in service intervals except DC-10-40 airplanes may use 5,000 hours' time in service intervals \n\n\n\n13,000-14,999\nPrior to accumulation of 16,000 hours' time in service\n3,000 hours' time in service intervals except DC-10-40 airplanes may use 5,000 hours' time in service intervals \n\n\n\n15,000-24,999\nWithin 1,000 additional hours' time in service after the effective date of this AD\n3,000 hours' time in service intervals except DC-10-40 airplanes may use 5,000 hours' time in service intervals \n\n\n\n25,000-33,000\nWithin 1,000 additional hours' time in service after the effective date of this AD\n1,000 hours' time in service intervals except DC-10-40 airplanes may use 2,000 hours' time in service intervals \n\n\t\t1.\tPerform the initial and repetitive tests indicated in paragraph 2 of McDonnell Douglas Alert Service Bulletin A24-99, dated June 19, 1978; or \n\n\t\t2.\tDeactivate the autopilot "land" mode in accordance with paragraph (d) of this AD; or \n\n\t\t3.\tReplace wire bundles per paragraph 2 of Service Bulletin 24-99, dated September 29, 1978. This option terminates the need for further testing as defined in this AD. \n\n\tc.\tIf wire-to-wire faults are found during the testing of (b)(1), before further flight: \n\n\t\t1.\tDeactivate the autopilot "land" mode in accordance with paragraph (d) of this AD; or \n\n\t\t2.\tReplace wire bundles with like serviceable parts and comply with the inspection schedule of paragraph (b) of this AD; or \n\n\t\t3.\tReplace wire bundles per paragraph 2 of Service Bulletin 24-99, dated September 29, 1978. This option terminates the need for further testing as defined in this AD. \n\n\td.\tDeactivation of the autopilot "land" mode shall be accomplished as follows: \n\n\t\t1.\tCoil and stow wires 1C512B24 and 2C512B24 or 1C512M24 and 2C512M24 as applicable. \n\n\t\t2.\tPlacard the autopilot "land" mode inoperative. \n\n\te.\tFor airplanes with the autopilot "land" mode deactivated for reasons other than those defined in this AD for a period in excess of the initial testing period defined in paragraph (b) that have wire bundles subject to testing as defined in this AD must be tested prior to reactivation as defined in paragraph (b). \n\n\tf.\tUpon request of an operator, the FAA assigned inspector, subject to prior approval of the Chief, Aircraft Engineering Division, FAA Western Region, may adjust the initial and repetitive tests at intervals specified in this AD to permit compliance at an established inspection period of the operator if the request contains substantiating data to justify the increase for that operator. \n\n\tg.\tEquivalent test procedures or modifications may be used when approved by the Chief, Aircraft Engineering Division, FAA Western Region. \n\n\th.\tSpecial flight permits may be issued in accordance with FAR's 21.197 and 21.199 to authorize operation of aircraft to a base where the modification required by this AD may be performed. \n\n\tThis amendment becomes effective March 23, 1979.