Closely Spaced Paralllel Operations (CSPO) Dependent Departures: Concept and Initial Assessments

The Federal Aviation Administration currently develops and implements capabilities of its Next Generation Air Transportation System (NextGen). Key benefits include increased airport capacity by reducing separation standards and enabling new operations in lower visibility conditions. NextGen's Closely Spaced Parallel Operations (CSPO) program investigates the operational concepts and performance requirements that enable the implementation of innovative standards and procedures for operations on closely spaced parallel runways across the National Airspace System. They include the CSPO Dependent Departure concept which aims to increase the operational efficiencies of departure operations. When operations are conducted under Instrument Flight Rules, departures from runways with centerlines spaced less than 2,500 feet currently require application of separation identical to the separation required for departures conducted on the same runway. The Dependent Departure concept capitalizes on CSPO runway spacing to enable lower initial separation requirements, effectively reducing the time interval applied between departing aircraft. This paper presents the CSPO Dependent Departure concept and its application to a range of operational scenarios. It describes the methodology developed for leveraging in-service data of actual operations to define reduced initial spacing requirements and support safety assessments of the operations. The results suggest, depending on the operational scenario, CSPO Dependent Departures with 15 to 52-percent reduced departure time intervals will meet the target level of safety established for the operations from a collision risk perspective.