Picture of In-flight 4D trajectory revision
Flight deck

In-flight 4D trajectory revision

  • Status: Completed
  • From January 2011 until October 2011

Supporting 4D trajectory revisions on the flight deck.

To accomplish air traffic growth in a safe and efficient way, future air traffic management concepts require aircraft to accurately execute 4-dimensional (4D) trajectories. A trajectory planned prior to takeoff, might, however, require in-flight revision. To support the flight crew in their task of accurately replanning a flight plan up to a metering fix, in 4 dimensions, a dedicated planning interface has been designed, adopting a cognitive systems engineering approach. The interface allows direct manipulation of the ground track and the descent profile. Constraints on trajectory planning are mapped onto alternative waypoint locations, highlighting the possibilities for acceptable ground track geometry in the horizontal situation display. In the vertical situation display, these constraints are mapped onto candidate top- and bottom-of-descent locations. It is hypothesized that the designed interface enables pilots to efficiently plan suitable 4D trajectories, while allowing for adaptive behavior and supporting situation awareness, even under high workload conditions.


Display design of the replanning interface, showing the waypoint affordance zone for estimated time of arrival (ETA) equal to required time of arrival (RTA) (1) and ETA within tolerances (2); labels regarding the speed (3) and altitude profile (4); the affordance zone of the top of descent (5) and an outline of the descent envelope (6); the maximum rate of descent (7); and a ground speed and throttle preview (8)