The above system with the radio direction finder on board ship is the only possible general navigational system through radio bearings. The systematic operation of radio-beacons during clear weather is being extended; correct bearings may be taken far be yond the range of any other aids. (R. R. W.) Airways Lighting in the United States.—The installation, operation and maintenance of the Federal Airways System, in cluding the lighting of the various airways comprising the whole network, are under the jurisdiction of the Administrator of the Civil Aeronautics Authority. Prior to the creation of the Author ity in 1938, these tasks had since 1926 been the responsibility of the Department of Commerce, administered successively by the Lighthouse Service and the Bureau of Air Commerce. With the completion of a $7,000,000 two-year airways modernization pro gram in 1939, there were in operation 24,249 miles of lighted airways equipped with 2,016 beacon lights, 238 radio range sta tions providing directional guidance, 68 radio position markers, 95 scheduled weather broadcasting stations, 23,658 miles of weather reporting teletypewriter circuits and an additional 10,676 miles of traffic control circuits, both with a total of 332 teletype writer stations, and 273 intermediate fields for emergency use.
Standard light equipment consists of 36-in. and 24-in. revolving beacons with parabolic mirror and 1,000 or 500 watt electric lamps developing approximately 2,000,000 beam candle-power and course light projectors flashing code numbers identifying the beacon along the airway and showing the course. Commercial electric power operates the apparatus mounted on steel skeleton towers. Engine-driven (gasoline or Diesel) generators in a small power house at the tower's foot furnish electricity if commercial power is unavailable. Astronomic clocks turn lights on and off. Boundary lights and cone markers 3ooft. apart outline intermedi ate fields, green range lights mark best runways and red lights mark air navigation obstructions. Internally lighted fabric wind cone on beacon towers at landing fields indicates wind direction and force (see also AERONAUTICS and AVIATION). (X.)
Administration.—The maintenance of aids to marine naviga tion is a function of the United States Coast Guard, having been placed under that organization on July 1, 1939, and consists of the maintenance of lighthouses, lightships, radio-beacons, fog sig nals, buoys, and beacons upon all navigable waters of the United States and its possessions; including Atlantic and Pacific coasts of continental United States, the Great Lakes, the Mississippi river and its tributaries, Puerto Rico, the approaches to the Panama canal, the Hawaiian islands, and Alaska.
The chief administrative officer is the Commandant of the Coast Guard, with headquarters at Washington, D.C. Under his direction the functions of establishment, construction, mainte nance, and operation of aids to navigation are carried on through administrative and engineering divisions in Washington, and by the various district offices. Because of the wide geographic distribu tion of aids to navigation on the sea coasts, the Great Lakes, and navigable rivers of the United States, with an aggregate coast line of over 40,000 miles, the field work of the service is carried on by district organizations. There are 13 Coast Guard districts, carry ing on lighthouse work, as well as other functions of the Coast Guard. Each district is under the supervision of a commander, assisted by a suitable engineering and administrative force, and equipped with the necessary supply and buoy depots, and with suitable vessels for the maintenance of the navigational aids.
The total cost of maintaining the aids to marine navigation for 1938 was $13,340,659, of which $2,847.809 was for new works, re pairs and improvements. Average costs for that year are: primary seacoast light station, $5,592; river post light, $122; sea-going tender (Atlantic), $70,332; exposed lightship, $28,300. Total aids in 1939, 29,606, of which 9,862 are lighted. The Philippines have 440 local aids, the Panama Canal 715, making a grand total for U.S. Territories of 30,761.