A separation standard for departures transitioning from terminal to en route control

The advent of radar surveillance over half a century ago enabled numerous Air Traffic Control (ATC) standards that continue to be in use today to safely separate aircraft. In the case of departure operations, the discrete increase of spacing requirements that applies when transitioning from terminal to en route control hampers Next Generation Air Transportation System (NextGen) goals of improving operational efficiencies. This paper proposes the concept of the Established-on-Departure Operation, or EDO, standard that capitalizes on improved navigational precision of Performance Based Navigation (PBN) operations. The concept incorporates current diverging procedures permitted in the terminal area as well as the concept of reduced divergence. The paper describes the requirements for its application and presents the analysis carried out to extend the applicability of a previously proposed standard for reduced-divergence operations. For Area Navigation (RNAV) Standard Instrument Departure (SID) operations, the analysis conservatively quantified a reduced divergence angle of 9 degrees, a 40-percent reduction in angular divergence when compared to today´s 15-degree requirement. In order to illustrate implementation examples and estimate potential benefits, the concepts were applied to the RNAV SID structure at The Hartsfield-Jackson Atlanta International Airport (ATL). For ATL alone, the estimates show a potential annual benefit of approximately $1.6 million per year. The standard concepts offer a suite of additional procedure design options not currently available to better accommodate airspace constraints and to increase the efficiency of departure operations transitioning from terminal to en route control.