ASTM F3442-25
Standard Specification for Detect and Avoid System Performance Requirements
| Standard number: | ASTM F3442-25 |
| Released: | 01.03.2025 |
| Status: | Active |
| Pages: | 51 |
| Section: | 15.09 |
1.1 This specification applies to smaller unmanned aircraft (UA) encountering crewed aircraft. It is meant to be applied in a “lower risk” (low- and medium-risk airspace as described by Joint Authorities for Rulemaking on Unmanned Systems (JARUS)) airspace environment; this is typically in Classes G and E airspace (below about 1200 ft (366 m) above ground level (AGL)), Class B, C, D (below about 400 ft to 500 ft (122 m to 152 m) AGL), below obstacle clearance surface (FAA Order 8260.3, as amended), or within Low Altitude Authorization and Notification Capability (LAANC) designated areas below the altitude specified in the facility map.
1.1.1 To satisfy assumptions on the likelihood of a mid-air collision, this specification applies to a UA with a maximum dimension (for example, wingspan, disc diameter) ≤ 25 ft (8 m), operating at airspeeds below 100 kts, and of any configuration or category.
1.1.2 Traffic encountered is expected to be mixed cooperative and non-cooperative traffic.
1.1.3 Traffic encountered could be operating via either instrument flight rules (IFR) or visual flight rules (VFR), or both.
1.1.4 This includes, but is not limited to, airspace where most aircraft are required to be broadcasting their position with a cooperative transponder (for example, within the Mode C veil and airspace defined by 14 CFR § 91.225 in the United States).
1.1.5 Encounters in typical airspace with general aviation and smaller crewed aircraft, including rotorcraft, small general aviation, crop dusters, ultralights, and light sport aircraft, are expected to occur infrequently and no more than one time per four days on average (or “infrequent” as per FAA Order 8040.6A).
1.1.6 The likelihood of an encounter in atypical airspace with general aviation and smaller crewed aircraft is lower than when operating in typical airspace.
1.1.7 If the JARUS Specific Operations Risk Assessment (SORA) 2.5 (or later) is used to assess airborne risk, airborne risk class (ARC)-d, areas with the greatest air risk, are out of scope.
1.2 Ultimate determination of applicability will be governed by the appropriate civil aviation authority (CAA).
1.3 This specification assumes no tactical air traffic control (ATC) separation services are provided to the UA.
1.3.1 This specification does not preclude, nor does it account for, strategic or operational traffic-based mitigations, for example, prior ATC coordination, UAS Traffic Management (UTM) services, or operator-imposed dynamic restrictions on the operating area.
1.4 While some architectures may have limitations due to external conditions, this specification applies to daytime and nighttime, as well as visual meteorological conditions (VMC) and instrument meteorological conditions (IMC).
1.4.1 This specification does not preclude, nor does it account for, using strategic or operational mitigations. These can include restricting the operational environment geographically or to certain times of day, or both, or placing limitations based on meteorological conditions.
1.5 This specification does not address avoidance of birds or natural hazards (for example, weather, clouds, terrain/obstacles).
1.6 This specification does not define a specific detect and avoid (DAA) architecture and is architecture agnostic. It will, however, define specific safety performance thresholds for a DAA system to meet to ensure safe resolution of encounters between a UA and crewed aircraft.
1.6.1 This specification defines a metric to assess the mitigation of a UA-to-UA mid-air collision, with specific safety performance thresholds to be addressed in future efforts. This metric aligns with the smaller NMAC (sNMAC) metric from RTCA DO-396.
1.7 This specification addresses the definitions and methods for demonstrating compliance to this specification, and associated considerations affecting DAA system integration (for example, detection range, required timeline to meet well clear, and proxy for mid-air collision safety targets).
1.7.1 This specification is not intended to be a minimum performance standard that can be referenced by a Technical Standard Order.
1.8 This specification highlights how different aspects of the system are designed and interrelated, and how they affect the greater UA system-of-systems to enable a developer to make informed decisions within the context of their specific UA application(s).
1.9 It is expected this specification will be used by diverse contributors or actors including, but not limited to:
1.9.1 DAA system designers and integrators,
1.9.2 Sensor suppliers,
1.9.3 UA developers,
1.9.4 Control Station designers,
1.9.5 Unmanned Aircraft System (UAS) service suppliers, and
1.9.6 Flight control designers.
1.10 Except for DAA system integrators for whom all the “shalls” in this specification apply, not all aspects of this specification are relevant to all actors/contributors. In some instances, the actor most likely to satisfy a requirement has been identified in brackets after the requirement; this is for information purposes only and does not indicate that only that actor may fulfill that requirement. Where not specified, the system integrator/proponent is assumed to be the primary actor. In all cases, the system integrator/proponent is responsible for all requirements and may choose to delegate requirements as is suitable to the system design. Nonetheless, familiarity with the entire specification will inform all actors/contributors of how their contributions affect the overall DAA capability and is strongly recommended.
1.11 Units—The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.
1.12 This specification is intended to serve as a detailed performance standard that, if met, accomplishes the safety intent of the requirement to “see and avoid;” for example, 14 CFR 91.113(b) may be used by a proponent to show compliance, and be accepted by the appropriate CAA. It is recognized that any means of compliance is one method, but not the only method, to show compliance with a regulatory requirement.
1.13 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.14 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.