All landing aircraft returning to the airport flight line shall leave the runway on the first available taxiway which is practical in order to keep the runways clear for approaching aircraft. Aircraft shall not make one hundred eighty degree turns on the runway after landing unless no taxiway is available, but shall continue straight ahead until reaching the first taxiway and shall clear the runway as soon as possible. (Ord. 1802 NCS §5 (part), 1990.)