Flight Deck Perspectives on Departure Procedures for Multiple Airport Route Separation

This paper documents portions of a study that examined current flight deck human factors issues associated with Performance-Based Navigation (PBN) departure procedures (DPs), with a focus on issues relevant to a proposed Air Traffic Control (ATC) operational concept called Multiple Airport Route Separation (MARS). MARS aims to improve the flow of air traffic to and from nearby busy airports by reducing the separation between aircraft flying along specially approved pairs of PBN instrument flight procedures (IFPs). As long as both aircraft stay on their cleared IFPs, ATC can be confident that they will remain procedurally separated. However, past research on PBN IFPs has shown that they may add complexity to pilot tasks, potentially increasing the risk of flightpath deviations. We present three components of the study. First, we met with technical airline pilots to get their insights on current operational issues with DPs. Second, we screened over 100 records from the Aviation Safety Reporting System (ASRS) with departure-related issues to curate a set of 20 records for in-depth analysis. Finally, we met with nine professional airline pilots to understand issues that occur during PBN DPs that might lead to flightpath deviations. We also employed a novel test method with the line pilots to examine how pilots might assess the threat posed by other aircraft during simulated MARS departure scenarios. In these scenarios, aircraft might appear in closer proximity and in locations that pilots would not normally expect, even as they stay on assigned routes. The results confirm that pilot tasks and strategies for flying PBN DPs depend upon the use of automated systems for lateral and vertical navigation. There are many ways that pilots may become vulnerable to flightpath deviations when interacting with automated systems. Departures are highly time-sensitive; poorly-timed interruptions and time pressure can create vulnerabilities. In terms of traffic-threat assessment during the simulated MARS departures task, our results indicated that pilots might seek additional information about a traffic aircraft and/or prepare to avoid a conflict. We discuss findings with respect to PBN departure operations in general and provide some specific insights for MARS operations.