<div class="htmlview paragraph">Increasing air traffic has produced an increase in midair collisions. This paper describes the airborne collision avoidance system (CAS), which is intended for use by large aircraft. It also describes the Dinade CAS, intended to be installed in small aircraft.</div> <div class="htmlview paragraph">In addition, the combination of the Dinade interrogator with a weather radar to conserve capital investment, space, weight, and power consumption, is discussed.</div>