The operational safety assessment of the unmanned vehicles is crucial for their subsequent practical use. The safety limit criteria used for the operation assessment, especially values closely related to the safety of persons and their vulnerability to collision with these vehicles, represent nowadays a significant limitation. This contribution presents the currently discussed and proposed human safety criteria for the UAS, evaluates the available data from the collision dynamic tests and computer modelling and provides the possibility to compare and evaluate these criteria on a validated set of data. A total of five small UAS, three multi-rotor quadcopters and two fixed-wing aircrafts were used to verify the current methods and serve as a basis for the assessment. The results of the measurements obtained through the crash tests demonstrate the excessive restrictiveness of the currently used kinetic energy threshold values and the limited value of some proposed criterions, e.g. the blunt criterion. On the contrary, they point to the appropriateness of the application of car vulnerability criterions. The UAS mass or kinetic energy tests represent an easily definable threshold value, however, the available data sets and the tests performed showed limitations of its applicability for the deformable and fragile UAS structures. The article aims to verify, based on its own impact tests, the adequacy of the evaluation of the safety criteria of the UAS operation in relation to the development of the current legislation that defines the conditions of use of these machines.

CTU Prague FTS Department of Forensic Experts in Transportation Konviktská 20 110 00 Prague 1 Czech Republic

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Commission Delegated Regulation (EU) 2019/945 of 12 March 2019 On Unmanned Aircraft Systems and on Third-Country Operators of Unmanned Aircraft Systems. Official Journal of the European Union, L152; 2019.

Commission Implementing Regulation (EU) 2019/947 of 24 may 2019 On the Rules and Procedures for the Operation of Unmanned Aircraft. Official Journal of the European Union, L152; 2019.

Notice of Proposed Amendment 2017-05 (B), Introduction of a Regulatory Framework for the Operation of Drones Unmanned Aircraft System Operations in the Open and Specific Category. European Aviation Safety Agency, RMT.0230; 2017.

Opinion No 01/2018, Introduction of a Regulatory Framework for the Operation of Unmanned Aircraft Systems in the ‘open’ and ‘specific’ Categories. European Aviation Safety Agency, RMT.0230; 2018.

Technical Opinion . European Aviation Safety Agency, RMT.0230; 2015. Introduction of a Regulatory Framework for the Operation of Unmanned Aircraft.

14 CFR Part 107 - small unmanned aircraft systems, 49 U.S.C. 106(f), 40101 note, 40103(b), 44701(a)(5); Sec. 333 of Pub. L. 112-95, 126 Stat. 75, [Online]. Available: https://ecfr.federalregister.gov/on/2018-03-05/title-14/chapter-I/subchapter-F/part-107.

Operation of Small Unmanned Aircraft Systems Over People. Federal Aviation Administration. 84 FR 3856, pp. 3856-3907, Docket No.: FAA-2018-1087.

Dalamagkidis K., Valavanis K.P., Piegl L.A. On unmanned aircraft systems issues, challenges and operational restrictions preventing integration into the National Airspace System. Prog. Aero Sci. 2008;44(7–8):503–519.

Clothier R., Williams B., Washington A. Development of a template safety case for unmanned aircraft operations over populous areas. SAE Techn. Paper Ser. 2015;2015

Weibel R., Hansman R.J. AIAA 4th Aviation Technology, Integration and Operations (ATIO) Forum. 2004. Safety considerations for operation of different classes of UAVs in the NAS.

Fraser C., Donnithorne-Tait D. Bristol International Unmanned Aerial Vehicle Systems (UAVS) Conference, Bristol, UK. 2011. An approach to the classification of unmanned aircraft.

Shelley A.V. A model of human harm from a falling unmanned aircraft: implications for UAS regulation. Int. J. Aviation, Aeronaut., Aerosp. 2016;3(3):1.

la Cour-Harbo A. Mass threshold for ‘harmless’ drones. Int. J. Micro Air Veh. 2017;9(2):77–92.

Arterburn D., et al. Final Report for the FAA UAS center of excellence task A4: UAS ground collision severity evaluation. ASSURE. 2017 https://www.assureuas.org/projects/deliverables/a4/ASSURE_A4_Final_Report_UAS_Ground_Collision_Severity_Evaluation.pdf Revision 2. [cit. 2020-11-20]. On-line:

Unmanned Aircraft Systems (UAS) Registration Task Force (RTF) Aviation Rulemaking Committee (ARC). Task Force Recommendations Final Report. (2015). [cit. 2020-11-20]. On-line: https://www.suasnews.com/wp-content/uploads/2016/04/Micro-UAS-ARC-FINAL-Report-4-2-16.pdf.

D. Arterburn et. al., “Annex A. UAH Final Report. Task A14: UAS Ground Collision Severity Evaluation 2017–2018, “Federal Aviation Administration, [Online]. Available: https://www.assureuas.org/projects/deliverables/a14/ASSURE_A14_Final_Report_UAS_Ground_Collision_Severity_Evaluation_2017-2019.pdf.

D. Arterburn et al., “Task A11 – Part 107 Waiver Request Case Study,” UAH Rotorcraft Systems Engineering and Simulation Center, Revision 1, 2016. [Online]. Available: https://www.assureuas.org/projects/deliverables/a11/Final%20Report.pdf.

G. Olivares et al., ”Annex B NIAR final Report. Task A14: UAS Ground Collision Severity Evaluation 2017-2018,” Federal Aviation Administration, Draft Report DOT/FAA/AR-XX/XX (to be published) [Online]. Available: https://www.assureuas.org/projects/deliverables/a14/ASSURE_A14_Final_Report_UAS_Ground_Collision_Severity_Evaluation_2017-2019.pdf.

J. Bolte et al., “Annex C. OSU Final Report.Task A14: UAS Ground Collision Severity Evaluation 2017–2018,” Federal Aviation Administration, Draft Report DOT/FAA/AR-XX/XX (to be published) [Online]. Available: https://www.assureuas.org/projects/deliverables/a14/ASSURE_A14_Final_Report_UAS_Ground_Collision_Severity_Evaluation_2017-2019.pdf.

Micro unmanned aircraft systems aviation rulemaking committee (ARC) 2016. https://www.suasnews.com/wp-content/uploads/2016/04/Micro-UAS-ARC-FINAL-Report-4-2-16.pdf ARC recommendations final Report [Online]. Available:

Magister T. The small unmanned aircraft blunt criterion based injury potential estimation. Saf. Sci. 2010;48(10):1313–1320.

Feinstein D.I., et al. Illinois Institute of Technology Research Institute; 1968. Personnel Casualty Study. Project No. J6067. AD 842573.

Feinstein D.I., et al. Illinois Institute of Technology Research Institute; 1968. Personnel Casualty Study. Project No. J6067. AD 842573.

Janser P.W., et al. Twentieth Explosive Safety Seminar; Virginia: 1982. Lethality of Unprotected Persons Due to Debris and Fragments.

Common Risk Criteria for National Test Ranges, RCC 321-07, Range Safety Group Risk Committee. Range Commanders Council, White Sands Missile Range; New Mexico: 2007.

Sturdivan L.M., Viano D.C., Champion H.R. Analysis of injury criteria to assess chest and abdominal injury risks in blunt and ballistic impacts. J. Trauma Acute Care Surg. 2004;56(3):651–663. PubMed

Koh C.H., et al. Weight threshold estimation of falling UAVs (Unmanned Aerial Vehicles) based on impact energy. Transport. Res. C Emerg. Technol. 2018;93:228–255.

Neades D.N., Rudolph R.R. Minutes of the Explosive Safety Seminar (21st), Texas. Vol. 2. 1984. An examination of injury criteria for potential application to explosive safety studies.

Range Safety Criteria for Unmanned Air Vehicles, Standard 323-18. Range Safety Group UAV Committee, Range Commanders Council; White Sands Missile Range, New Mexico: 2018.

Range safety criteria for unmanned air vehicles. Rationale and Methodology Supplement. Range Safety Group UAV Committee, Range Commanders Council; White Sands Missile Range, New Mexico: 1999.

Zaker T.A., et al. 1970. Fragmentation Hazard Study, Phases I and II. Final Report, Contract DARC-04-69-C-0056.

Henderson J. 34th Department of Defence Explosives Safety Board Seminar, Portland, Oregon. 2010. Lethality criteria for debris generated from accidental explosions, ADM002313.https://apps.dtic.mil/dtic/tr/fulltext/u2/a532158.pdf [Online]. Available:

Radi A. Civil Aviation Safety Authority. Tech.Rep; Australia: 2013. Human injury model for small unmanned aircraft impacts.https://www.casa.gov.au/sites/default/files/_assets/main/airworth/papers/human-injury-model-small-unmanned-aircraft-impacts.pdf?acsf_files_redirect [Online]. Available:

Bir C., Viano D.C. Design and injury assessment criteria for blunt ballistic impacts. J. Trauma Acute Care Surg. 2004;57(6):1218–1224. PubMed

Raymond D., et al. Tolerance of the skull to blunt ballistic temporo-parietal impact. J. Biomech. 2009;42(15):2479–2485. PubMed

49 Cfr Part 571 - FEDERAL MOTOR vehicle safety standards, 49 U.S.C. 322, 30111, 30115, 30117, and 30166. [Online]. Available: https://ecfr.federalregister.gov/current/title-49/subtitle-B/chapter-V/part-571.

Regulation No 94 of the Economic Commission for Europe of the United Nations (UN/ECE) — Uniform provisions concerning the approval of vehicles with regard to the protection of the occupants in the event of a frontal collision [Online]. Available: https://op.europa.eu/en/publication-detail/-/publication/ed1e0b9a-024e-11e2-8e28-01aa75ed71a1.

Mertz H.J., Irwin A.L., Prasad P. Biomechanical and scaling bases for frontal and side impact injury assessment reference values. Stapp Car Crash J. 2003;47:155–188. PubMed

Mertz H.J., Prasad P., Nusholtz G. Head injury risk assessment for forehead impacts. SAE Trans. 1996:26–46.

Duma S.M., et al. Small female head and neck interaction with a deploying side airbag. Accid. Anal. Prev. 2003;35(5):811–816. PubMed

Gurdjian E.S., Webster J.E., Lissner H.R. Studies on skull fracture with particular reference to engineering factors. Am. J. Surg. 1949;78(5):736–742. PubMed

Eppinger R., et al. NHTSA; 1998. Development of Improved Injury Criteria for the Assessment of Advanced Automotive Restraint Systems.https://www.nhtsa.gov/sites/nhtsa.dot.gov/files/rev_criteria.pdf [Online]. Available:

Hayes W. Forensic injury biomechanics. Annu. Rev. Biomed. Eng. 2007;9:55–86. PubMed

Kraus J., Kleczatský A., Hulínská Š. Social, technological, and systemic issues of spreading the use of drones. Transport. Res. Procedia. 2020;51:3–10.

Impact analysis assessment of UAS collision with a human body