Paired approach operational concept

The paired approach procedure is intended to facilitate IFR approaches to closely spaced parallel runways i.e., runways separated by less than 2500 feet. Parallel ILS approaches cannot currently be conducted under instrument meteorological conditions to such runways. The paired approach procedure requires aircraft to maintain longitudinal separations within a specific band on approach to the runways such that protection is provided against collision as well as wake vortex hazards. The procedure requires air traffic control to pair eligible aircraft and deliver them to the final approach courses within certain longitudinal tolerances. The flight crew of the trailing aircraft then conducts the paired approach procedure with a set of cockpit-based spacing tools. These spacing tools help the flight crew to achieve and maintain a defined longitudinal spacing prior to the final approach fix. Real time simulations were conducted with line pilots and full performance level controllers in a medium fidelity simulation. The simulation capability included a commercial twin jet flight deck and an ATC platform, which in turn, were used to define flight deck tasks, develop cockpit display and spacing tool requirements, and define ATC procedures and controller tasks. This paper describes these ATC procedures, pilot and controller tasks and cockpit display requirements. It also discusses ways in which the spacing concept and tools so developed are being applied and developed further for other approach spacing applications.