Hács
High Angle Control System (HACS) was a British anti-aircraft fire-control system employed by the Royal Navy from 1931 onwards and used widely during World War II. HACS calculated the necessary deflection required to place an explosive shell in the location of a target flying at a known height, bearing and speed.
Read more about Hács: Early History, Development, The Fuze Keeping Clock, The Auto Barrage Unit, Wartime Experience, Radar and The Mark VI Director, HACS Systems in Use or Planned in August 1940