ISO 5312:2023

Overview

ISO 5312:2023 establishes a standardized evaluation and test method for sharp injury to the human body caused by rotor blades of civil small and light unmanned aircraft (UA). It applies to multicopters, unmanned helicopters and other rotorcraft with a maximum take-off mass of 0.25 kg to 4 kg (ISO 21895 levels II and III). The standard defines injury types (laceration and puncture), a three‑level sharp injury scale, test principles, required equipment, procedures, and result evaluation criteria to support safety assessment and product development.

Key topics and technical requirements

• Scope & definitions: Sharp injury = laceration (circumferential blade-tip motion) or puncture (blade end radial movement).
• Sharp injury scale: Three levels - Scale 1 (scratches/bruises), Scale 2 (minor injuries, first aid), Scale 3 (injuries requiring medical intervention). Scales 1–2 are considered acceptable; Scale 3 is unacceptable.
• Analysis vs test levels: Compliance can be demonstrated by analytical criteria or physical tests. Analytical rules include blade material and tip geometry limits (e.g., non‑metal blades and minimum leading-edge/rounded tip radius ≥ 1 mm; square tip chord rules; foldable propellers must fold back on contact).
• Required test equipment:
  • Accumulator loading device: adjustable launch speed 0–25 m/s; accuracy ±0.1 m/s (0–5 m/s) and ±0.5 m/s (5–25 m/s).
  • Speed measuring device: accuracy ±0.1 m/s.
  • High‑speed camera: ≥1 000 frames/s to record blade motion and post-impact behaviour.
  • Target fixture: installation precision ±1 mm position and ±1° angle.
  • Bionic skin: surface + foam backing; test piece dimensions ≥1.5× rotor blade size.
• Test conditions and reporting: Specifies test site/environment, staff competency, interruption/resumption rules, post-test inspection and a structured evaluation/reporting format. Test results include wound length and depth criteria (Scale 3 injuries are unacceptable).

Applications and users

ISO 5312:2023 is intended for:

• Drone and rotor‑blade manufacturers - to design safer blades and demonstrate compliance.
• Independent test laboratories - to perform standardized sharp‑injury tests using bionic skin and calibrated equipment.
• Certification bodies and regulators - to assess product safety for market access and operation rules.
• R&D and safety engineers - to evaluate blade design, materials and mitigations (folding tips, rounded geometries).
• Operators and procurement teams - to specify safety requirements for small and light UA.

Related standards

• ISO 21384‑4 (UA vocabulary)
• ISO 21895 (categorization/classification of civil UA)

Keywords: ISO 5312:2023, unmanned aircraft safety, rotor blade injury test, sharp injury scale, bionic skin, multicopter safety, drone blade testing.