FAA UAS Center of Excellence Task A4: UAS Ground Collision Severity Evaluation

This evaluation documents the Unmanned Aerial System (UAS) platform characteristics related to the severity of UAS ground collision based upon the literature search of over 300 publications from the automotive industry, consumer battery market, toy standards, and other fields. The literature search included the evaluation of various criteria developed for human blunt force trauma injuries, penetration injuries and laceration injuries. These injury types represent the most significant threats to the non-participating public and crews operating Micro UAS (mUAS) and Small UAS (sUAS) platforms. The kinetic energy for the worst case terminal velocity or maximum cruise airspeed, energy density, and rotor diameter are the most significant UAS characteristics contributing to blunt force trauma penetration and laceration injuries, respectively. Two impact kinetic energy methodologies are presented to provide a risk and scenario based approach to determining kinetic energy thresholds for safe UAS operations. Parachute mitigations and the application of area weighted kinetic energy methodology for two scenarios are presented to outline thresholds for a broader range of vehicle weights to conduct flight over people than is currently possible with the unmitigated vehicle designs currently available. An initial investigation of energy transfer based on crash testing and dynamic modeling was conducted along with finite element analysis for human head and torso impacts. The crash test results and subsequent analysis strongly suggest that Range Commander’s Council (RCC)-based thresholds are overly conservative because they do not accurately represent the collision dynamics of elastically-deformable sUAS with larger contact areas in comparison to the metallic debris analysis methods for high speed missiles on the national test ranges. Lithium Polymer batteries dominate the mUAS and sUAS market as the principle energy source for these platforms. While many of the manufacturers state they test their batteries in accordance with Lithium Ion battery testing methods for consumer electronics, the batteries are rarely marked to show compliance with these standards and many of the test methods are not consistent with the forces and energy levels associated with ground collision impact energy. More research is required to address the fire hazard and impact hazard presented by the broad spectrum of batteries and battery chemistries used in mUAS and sUAS platforms. Twenty-three knowledge gaps were identified during the execution of the literature search and are recommended for future research efforts.

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• Record URL:
  https://rosap.ntl.bts.gov/view/dot/32209
• Corporate Authors:

  University of Alabama, Huntsville

  Huntsville, AL  United States 

  University of Kansas, Lawrence

  Lawrence, KS  United States  66045

  Mississippi State University, Mississippi State

  Mississippi State, MS  United States  39762

  Embry-Riddle Aeronautical University

  ,    

  Federal Aviation Administration

  800 Independence Avenue, SW
  Washington, DC  United States  20591
• Authors:
  • Arterburn, David
  • Ewing, Mark
  • Prabhu, Raj
  • Zhu, Feng
  • Francis, David
• Publication Date: 2017

Language

• English

Media Info

• Media Type: Digital/other
• Edition: Final Report
• Features: Appendices; Figures; Photos; References; Tables;
• Pagination: 194p

Subject/Index Terms

• TRT Terms: Air transportation crashes; Aviation safety; Crash tests; Drones; Evaluation and assessment; Finite element method; Head; Injury severity; Kinetic energy; Literature reviews; Lithium batteries; Recommendations; Standards
• Uncontrolled Terms: Parachutes
• Subject Areas: Aviation; Safety and Human Factors; Vehicles and Equipment;

Filing Info

• Accession Number: 01634887
• Record Type: Publication
• Files: NTL, TRIS, ATRI, USDOT
• Created Date: May 17 2017 5:05PM