01301nam 2200385Ia 450 991069792530332120090122142523.0(CKB)5470000002393743(OCoLC)299064109(EXLCZ)99547000000239374320090122d1977 ua 0engurmn|||||||||txtrdacontentcrdamediacrrdacarrierImportance of transponder operation and altitude reporting[electronic resource][Washington, D.C.] :Dept. of Transportation, Federal Aviation Administration,[1977]2 pages digital, PDF fileAdvisory circular ;AC no. 91-50Title from PDF caption (viewed Jan. 22, 2009)."8/24/77."TranspondersAirplanesRadio equipmentAltitudesAirplanesRadarEquipment and suppliesAltitudesTransponders.AirplanesRadio equipmentAltitudes.AirplanesRadarEquipment and suppliesAltitudes.GPOGPOGPOBOOK9910697925303321Importance of transponder operation and altitude reporting3103795UNINA