AD 79-18-03

Active

Wing/Antenna Anti-Ice System

Key Information
79-18-03
Active
November 01, 1979
Not specified
Unknown
39-3603
Applicability
["Aircraft"]
["Large Airplane"]
The Boeing Company
DC-10-10 DC-10-10F DC-10-30 DC-10-30F (KC-10A, KDC-10) DC-10-40
Regulatory Text

79-18-03 MCDONNELL DOUGLAS: Amendment 39-3541 as amended by Amendment 39-3603. Applies to DC-10-10, -10F, -30, -30F and -40 airplanes. Serial numbers corresponding to manufacturer's fuselage Numbers 1 through 258, certificated in all categories. \n\n\tCompliance is required as indicated. \n\n\tTo reduce the possibility of an unannounced anti-ice system failure accomplish the following, unless modified per Paragraph (c) of this AD. \n\n\ta.\tWithin the next 300 hours' time in service from the effective date of this AD, unless previously accomplished within the last 3,000 hours' time in service, accomplish the tests specified below. \n\n\t\tTEST PROCEDURE FOR WING/ANTENNA ANTI-ICE SYSTEM PASSIVE FAILURES \n\n\t\t1.\tRemove power from all AC and DC buses. \n\n\t\t2.\tOpen "BATT DIRECT & LEFT EMER DC FEED" circuit breaker on overhead CB panel. \n\n\t\t3.\tDisconnect P1-837 at center accessory compartment right hand (CAC-R) disconnect panel. \n\n\t\t4.\tRestore power to DC buses 1 and 3. (Other buses may be energized if desired.) \n\n\t\t5.\tPressurize No. 3 pneumatic system to at least 15 psig per instructions in Maintenance Manual Chapter 36-00-00. \n\n\t\t6.\tPlace WING & ANT ANTI-ICE switch to TEST position and verify that WING & ANT ANTI-ICE DISAGREE light comes on and goes off. \n\n\t\t\tCAUTION: WING ICE PROTECTION MUST NOT BE OPERATED IN TEST POSITION ON THE GROUND WITH ENGINES OR APU OPERATING OR WITH PNEUMATIC GROUND SUPPLY CONNECTED FOR MORE THAN 30 SECONDS. FAILURE TO OBSERVE THIS PRECAUTION CAN RESULT IN OVERHEATING WING LEADING EDGES, CAUSING DAMAGE. \n\n\t\t\tNOTE: The above caution is not applicable if an external ground pneumatic source with air temperature controlled at 190 degrees F (88 degrees C) or less is used. \n\n\t\t7.\tRelease WING & ANT ANTI-ICE switch and verify WING & ANT DISAGREE light comes on and goes off. \n\n\t\t8.\tDepressurize No. 3 pneumatic system, remove power from all AC and DC buses, and verify "BATT DIRECT & LEFT EMER DC FEED" circuit breaker is open.9.\tReconnect P1-837 at CAC-R panel and restore power to aircraft as required. \n\n\t\t10.\tOpen "WING & ANT ANTI-ICE DISAGREE LTS" circuit breaker on upper main CB panel. \n\n\t\t11.\tIn lower galley or forward cargo area as applicable, gain access to antenna valve. \n\n\t\t12.\tDisconnect P1-2472 from antenna valve position switches. \n\n\t\t13.\tClose circuit breaker listed in Step 10. \n\n\t\t14.\tPressurize No. 3 pneumatic system to at least 15 psig per instructions in Maintenance Manual Chapter 36-00-00. \n\n\t\t15.\tPlace WING & ANT ANTI-ICE switch to TEST position and verify that WING & ANT ANTI-ICE DISAGREE light comes on and goes off. \n\n\t\t\tCAUTION: WING ICE PROTECTION MUST NOT BE OPERATED IN TEST POSITION ON THE GROUND WITH ENGINES OR APU OPERATING OR WITH PNEUMATIC GROUND SUPPLY CONNECTED FOR MORE THAN 30 SECONDS. FAILURE TO OBSERVE THIS PRECAUTION CAN RESULT IN OVERHEATING WING LEADING EDGES, CAUSING DAMAGE. \t\t\t\n\n\t\t\tNOTE: The above caution is not applicable if an external ground pneumatic source with air temperature controlled at 190 degrees F (88 degrees C) or less is used. \n\n\t\t16.\tRelease WING & ANT ANTI-ICE switch and verify WING & ANT DISAGREE light comes on and goes off. \n\n\t\t17.\tOpen circuit breaker listed in Step 10. \n\n\t\t18.\tReinstall P1-2472 connector on antenna valve. \n\n\t\t19.\tRestore aircraft to normal operating condition. \n\n\t\t\tNOTE: Steps 1 through 7 check the integrity of the VHF antenna anti-ice valve and monitoring circuit. Steps 10 through 16 check the integrity of the right wing anti-ice valve and monitoring circuit. \n\n\tb.\tIf Steps a.6 and 7 or a.15 and 16 are not satisfactorily accomplished, repair the unsatisfactory condition, or restrict the aircraft from flight in icing conditions. \n\n\tc.\tWithin one year from the effective date of this AD provide for performance monitoring of the wing and antenna anti-ice systems by separate lights in a manner approved by the Chief, Aircraft Engineering Division, FAA Western Region. \n\n\tNote: McDonnell Douglas Service Bulletin 30-47 dated December 5, 1978 and/or Revision 1 dated May 22, 1979 provide a satisfactory method of accomplishment. \n\n\td.\tAlternative inspections, modifications or other actions which provide an equivalent level of safety may be used when approved by the Chief, Aircraft Engineering Division, FAA Western Region. \n\n\tAmendment 39-3541 became effective September 29, 1979. \n\n\tThis Amendment 39-3603 becomes effective November 1, 1979.

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References
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--- - Part 39
FAA Documents