Flight Trajectory Options to Mitigate the Impact of Unmanned Aircraft Systems (UAS) Contingency Trajectories-A Concept of Operations

By John Bernard , Andrew Lacher

This concept of operations proposes to re-purpose a Traffic Flow Management System capability, scheduled for implementation in 2014, to facilitate coordination of UA contingency trajectories between UA remote pilots and the air traffic management system.

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​No NextGen Air Transportation System (NextGen) mid-term automation capability is currently planned for storing and processing Unmanned Aircraft (UA) contingency trajectories. Contingency trajectories are plans that would be executed in case of a loss of the command and control (C2) link between the pilot’s control station and the UA, or some other unexpected event. As a result, controllers have limited situational awareness and cannot depict an unmanned aircraft’s flight trajectory on air traffic management displays during a contingency event.

This concept of operations proposes to re-purpose a Traffic Flow Management System (TFMS) capability, scheduled for implementation in 2014, to facilitate coordination of UA contingency trajectories between UA remote pilots and the air traffic management (ATM) system. A Trajectory Option Set (TOS) message could be leveraged by the remote pilot to communicate UA contingency trajectories. Optional to the concept, augmentations to existing TOS specifications are described, which could quickly communicate to ATC a UA’s contingency trajectory based on UA problem type (e.g., lost C2 link or other type of emergency situation).

Leveraging a mid-term capability such as TOS, (with essentially no modifications other than Unmanned Aircraft System (UAS)-specific procedures) to handle UAS contingency trajectories would help address a critical integration issue for UAS (lost C2 link), while providing greater predictability, consistency, and situation awareness for controllers while enabling the use of ATM decision support systems.​