Abstract: A radar system which time shares the use of a common radar head to perform functions associated with Air Surveillance Radar (ASR) and Precision Approach Radar (PAR) systems, i.e., for respectively displaying information to an air traffic controller useful for tracking an aircraft's approach to an airport and then guiding said aircraft along a preferred glideslope approach to a runway. In accordance with a significant feature of a preferred embodiment, a common radar head is comprised of an azimuth antenna capable of using radar beams to scan, e.g., electronically, a subsidiary scan arc, i.e., less than .+-.90.degree., mounted on a rotational scan apparatus that directs said radar beams within a principal scan arc, a full circle (360.degree.), by continuously rotating, e.g., mechanically, said azimuth antenna at an essentially constant rate.