This incumbent controls air traffic on and within vicinity of airport according to established procedures and policies to prevent collisions and to minimize delays arising from traffic congestion. This worker answers radio calls from arriving and departing aircraft and issues such landing and takeoff instructions and information as runway to use, wind velocity and direction, visibility, taxiing instructions, and pertinent data on other aircraft operating in vicinity. This specialist transfers control of departing flights to and accepts control of arriving flights from air traffic control center, using telephone or interphone, alerts airport emergency crew and other designated personnel by radio or telephone when airplanes are having flight difficulties. The worker pushes buttons or pulls switches to control airport floodlights and boundary, runway, and hazard lights, and scans control panel to ascertain that lights are functioning, operates radio and monitors radarscope to control aircraft operating in vicinity of airport. The specialist also receives cross-country flight plans and transmits them to air traffic control center, signals aircraft flying under visual flight rules, using electric signal light or flags, may control cross-runway traffic by radio directions to guards or maintenance vehicles, and may keep written record of messages received from aircraft.