The US Army's Aerial Common Sensor was conceived to combine the RC-12 Guardrail Common Sensor and the RC-7 Airborne Reconnaissance Low into a single aircraft. David Willis explains how the proposed system was scuppered by its own ambitions.
The Aerial Common Sensor (ACS) consisted of five subsystems, comprising the sensor suite; the processing, exploitation and dissemination equipment; the airborne communications and datalinks; the ground-processing and an airborne platform. Performance criteria for the first of these included a speed greater than 345kts and a threshold altitude of 37,000ft, ruling out a turboprop. Another requirement was that the aircraft be able to carry a payload of 10,000lbs.