International Journal of Aviation Sciences (IJAS)


An experiment was conducted in an austere desert location (entirely lacking artificial light pollution) to evaluate visual observers’ ability to maintain line of sight with a light-sport manned aircraft and a small unmanned aircraft system (sUAS; Raven RQ-11B or Wasp III) and predict imminent collisions between them. We investigated the impact of night and dusk operational settings on observers’ performance as compared to daytime and manipulated the placement of the critical visual observer in relation to the sUAS pilot. Analyses revealed that the light-sport aircraft was identified at significantly farther distances at night and dusk than during the day, and that observers tracked the sUAS better at night and at dusk than during the day. Furthermore, signal detection theory analyses revealed superior collision anticipation rates when the critical visual observer was co-located with the sUAS pilot. Implications for night flight safety and sUAS integration into the National Airspace System are discussed.

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