Systems, methods and protocol for assuring separation of aircraft during parallel approaches. The systems, methods and protocol function in cooperation with existing TCAS to facilitate approaches of multiple aircraft on closely-spaced parallel runways. The systems, methods and protocol utilize data transmissions from equipped aircraft to obtain tracking information which is used in separation algorithms to generate alerts to an observer of possible threats. The systems, methods and protocol facilitate parallel approaches to closely-spaced parallel runways under Instrument Approach Procedure.
