On April 28, 2017, the Federal Aviation
Administration (FAA) in cooperation with the Alliance for System Safety of UAS
through Research Excellence (ASSURE). issued a UAS Ground Collision Severity
Evaluation Final Report examining understanding the risks of allowing small
unmanned aircraft – or drones – to fly over people. The consortium that
conducted the research includes the University of Alabama-Huntsville;
Embry-Riddle Aeronautical University; Mississippi State University; and the
University of Kansas, through the Alliance for System Safety of UAS through
Research Excellence (ASSURE). ASSURE represents 23 of the world's leading
research institutions and 100 leading industry and government partners. It
began the research in September 2015.
This research is a critical component
to the FAA’s deliberations as the agency prepares the next generation of sUAS
rules to allow commercial operation beyond visual line of sight (VLOS). It is also a fundamental element of the FAA’s
mission of Safety First!
The group also reviewed more than
300 publications from the automotive industry and consumer battery market, as
well as toy standards and the Association for Unmanned Vehicle Systems
International (AUVSI) database. Finally, the team conducted crash tests,
dynamic modeling, and analyses related to kinetic energy, energy transfer, and
crash dynamics. When the studies were complete, personnel from NASA, the
Department of Defense, FAA chief scientists, and other subject matter experts
conducted a strenuous peer review of the findings.
The FAA indicated that the studies
identified three dominant injury types applicable to small drones:
- Blunt force trauma – the most significant contributor to fatalities
- Lacerations – blade guards required for flight over people
- Penetration injuries – difficult to apply consistently as a standard
The UAS Ground Collision Severity
Evaluation Final Report showed multi-rotor drones fall more slowly than the
same mass of metal due to higher drag on the drone. Unlike most drones, wood
and metal debris do not deform and transfer most of their energy to whatever
they hit. Also, the lithium batteries that power many small drones need a
unique standard to ensure safety.
The team recommended continued
research to refine the metrics developed. The Final Report indicated that team
members suggested developing a simplified test method to characterize potential
injury, and validating a proposed standard and models using potential injury
severity test data.
The FAA indicated that the second
phase of ASSURE’s research is set to begin in June 2017, and will examine the
risks of collisions with aircraft. This
type of collision is perhaps the greatest safety risk posed by sUAS operation
in the National Airspace System. The results
of the research will be closely watched and are highly anticipated.
The entire text of the UAS Ground
Collision Severity Evaluation Final Report can be viewed here
