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U.S. Department of Transportation U.S. Department of Transportation Icon United States Department of Transportation United States Department of Transportation

Elevating Air Traffic Safety and Efficiency during Departure with Flight Deck Insights

Monday, May 18, 2026
A simulated Boeing 737 flight deck navigation display depicting an aircraft (unfilled white triangle) on a published instrument departure procedure (magenta line) with a traffic aircraft overlay from the Traffic Alert and Collision Avoidance System (filled cyan diamond). The display indicates that the traffic aircraft is just 200 feet below the aircraft and climbing.
A simulated Boeing 737 flight deck navigation display depicting an aircraft (unfilled white triangle) on a published instrument departure procedure (magenta line) with a traffic aircraft overlay from the Traffic Alert and Collision Avoidance System (filled cyan diamond). The display indicates that the traffic aircraft is just 200 feet below the aircraft and climbing. (U.S. DOT Volpe Center) 

FAA partnered with the U.S. DOT Volpe Center’s team of technical experts to study Multiple Air Route Separation (MARS)—an innovative air traffic concept expanding the use of Performance Based Navigation (PBN) in the terminal area to boost traffic flow around congested airports. MARS has the potential to bring aircraft closer together in busy terminal airspace, demanding precise adherence to flight paths to maintain safety under reduced separation. The U.S. DOT Volpe Center’s earlier work identified factors that can impact the flight crew’s ability to stay on the desired flight path. Understanding how pilots experience and manage these tighter conditions is vital to shaping FAA guidance and ensuring efficient air traffic flow.

The U.S. DOT Volpe Center team’s research included the following components.

  • Expert Consultation: Engaged technical pilots to pinpoint potential flight deck issues that might arise in a MARS departure operation.
  • Real-world Analysis: Reviewed a curated set of 20 NASA Aviation Safety Reporting System reports detailing flight path deviations during PBN departures. 
  • Pilot Perceptions: Interviewed pilots and presented periodic snapshots of MARS departure scenarios on a simulated flight deck display to gauge traffic threat awareness and response strategies.

The U.S. DOT Volpe Center’s research informs FAA decision-making for regulations and guidance on PBN departures and supports safety risk management for future MARS phases. Some initial findings include: 

  • Typical Flight Path Deviations Arise Intentionally and Unintentionally: Intentional deviations respond to external factors like weather or equipment problems. Unintentional deviations more often stem from task overload or air traffic control (ATC) clearance changes.
  • Traffic Proximity Intensifies Pilot Vigilance: During simulated MARS departures, pilots paid more attention to traffic as it got closer, prompting them to consider early maneuvers or ATC communication to guarantee safety.
  • Rising Procedural Complexity: PBN departures now include more precise altitude constraints—waypoints with altitude requirements rose from 17 percent in 2015 to 22 percent in 2023. Managing multiple constraints can increase pilot workload during critical phases.

Building on the U.S. DOT Volpe Center’s earlier research, FAA’s phased rollout of MARS can now rely on these critical flight deck insights to balance efficiency gains with safety assurance—ultimately enabling smoother, safer airspace operations across the nation. The full research findings can be accessed here: Flight Deck Perspectives on Performance-based Navigation (PBN) Departure Procedures. The U.S. DOT Volpe Center team also summarized highlights from its research here: Flight Deck Perspectives on Departure Procedures for Multiple Airport Route Separation.

About the U.S. DOT Volpe Center

Since 1970, the U.S. DOT Volpe Center has advanced transportation innovation for the public good, providing multimodal applied research, collaborating with federal, state, and industry partners, and multidisciplinary technical leadership and expertise to solve complex transportation challenges. Learn more at www.volpe.dot.gov.