Safety of cooperative collision avoidance for unmanned aircraft

For unmanned aircraft to be routinely used in civil airspace, an effective collision avoidance function is one area deemed essential for safe operation. Like manned aircraft, avoiding collisions with transponder-equipped, or "cooperative" traffic is among the primary hazards. This paper discusses the necessity of developing various models of environmental and system components in the collision avoidance functional chain. Potential sensitivities and shortcomings of the TCAS collision avoidance system for unmanned aircraft are discussed. The analysis method of fast-time simulation can develop a rich sample of collision encounter events from the numerous statistical distributions. This provides an established means to demonstrate system compliance with safety targets, when they are established