Evaluating the Preventive Alert Function for UAS Detect and Avoid Systems

The research effort was an examination of the alerting level for the Detect and Avoid (DAA) Preventive Alert function as defined by the Radio Technical Commission for Aeronautics (RTCA) Special Committee 228 Detect and Avoid Working Group in the DAA Phase I Minimum Operational Performance Standards (MOPS) (RTCA DO-365B). The term “alert” is used in this report generically to include Warnings, Cautions, and Advisories. RTCA DO-365B specifies that the DAA Preventive Alert is a Caution-level alert, but the DAA Preventive Alert does not require an action, so it matches the definition of an Advisory-level alert as defined in § 25.1322. Consequently, the authors were interested in understanding whether showing the DAA Preventive Alert as an Advisory (rather than a Caution) would influence the pilot’s behavior and potentially compromise safety of flight. The authors conducted a simulation study with 32 unmanned aircraft system pilots who were asked to perform a fire-fighting mission that required them to locate and photograph “hot spots” while piloting their aircraft. Most of the mission was flown following pre-programmed waypoints. During the mission, the presence of other traffic coming close to ownship would trigger traffic alerts. Of primary interest was pilots’ response to the DAA Preventive Alert, which would sometimes be followed by a higher-importance Corrective or Warning alert that required the pilot to maneuver their aircraft to avoid losing well clear from the other aircraft. The results suggest that changing the Preventive Alert level from a Caution-level to an Advisory-level alert will not compromise safety of flight as it relates to traffic avoidance. The level of Preventive Alert did not affect the probability of losing well clear nor the pilot response time to maneuver to maintain well clear. Although pilots who received only an Advisory-level Preventive Alert were less likely to see traffic until a Corrective or Warning Alert occurred, this did not affect their ability to remain well clear. The data collected here are only preliminary. Further research is needed to formally reduce the status level of the Preventive Alert. It is also important to understand whether pilots would consider a Caution-level Preventive Alert a nuisance or distraction to the pilot, since it implies that a corrective action is needed when no action may be required.

• Record URL:
  https://www.faa.gov/data_research/research/med_humanfacs/oamtechreports/2020s/media/202117.pdf
• Record URL:
  https://rosap.ntl.bts.gov/view/dot/57235
• Corporate Authors:

  FAA Civil Aerospace Medical Institute

  6500 S MacArthur Boulevard
  Oklahoma City, OK  United States  73125

  FAA Civil Aerospace Medical Institute

  Cherokee Nation Support, Service, and Solutions
  Oklahoma City, OK  United States  73125

  Federal Aviation Administration

  Office of Aerospace Medicine, 800 Independence Avenue, SW
  Washington, DC  United States  20591
• Authors:
  • Williams, Kevin W
  • Mofle, Theodore C
  • Choi, Inchul
• Publication Date: 2021-6

Language

• English

Media Info

• Media Type: Digital/other
• Features: Appendices; Figures; Photos; References; Tables;
• Pagination: 68p

Subject/Index Terms

• TRT Terms: Air pilots; Aviation safety; Crash avoidance systems; Flight simulators; Unmanned aircraft systems; Warning systems
• Identifier Terms: Radio Technical Commission for Aeronautics
• Subject Areas: Aviation; Safety and Human Factors;

Filing Info

• Accession Number: 01778628
• Record Type: Publication
• Report/Paper Numbers: DOT/FAA/AM-21/17
• Files: NTL, TRIS, ATRI, USDOT
• Created Date: Aug 3 2021 3:31PM