The concept of intermittent positive control is to issue commands to normally uncontrolled aircraft only when it is necessary to avoid a hazardous midair circumstance. This concept would depend on a hardware environment which provides reliable location and identification of all aircraft in the protected airspace. A digital computer would use this track and ID information to detect potential conflicts and to calculate commands for transmission to the aircraft which would resolve them. The paper describes a model of the airspace and its use in analyzing the frequency of generated commands. Also, a description of the basic computer algorithm to be used for the conflict detection and resolution function is given.