Minimum Operational Performance Standards (MOPS) for Detect and Avoid (DAA) Systems
|Publication Date:||18 March 2021|
This document contains Minimum Operational Performance Standards (MOPS) for Detect and Avoid (DAA) systems used in Unmanned Aircraft Systems (UAS) transiting through Class B, C, D, E, and G airspace and performing extended operations higher than 400' Above Ground Level (AGL) in Class D, E (up to Flight Level (FL) 180), and G airspace. It includes equipment to enable UAS operations in Terminal Areas during approach and departure in Class C, D, E and G airspace and off-airport locations. It does not apply to small UAS (sUAS) operating in low-level environments (below 400') or other segmented areas. Likewise, it does not apply to operations in the Visual Flight Rules (VFR) traffic pattern of an airport or to surface operations. For a complete description of operations and environments, refer to Appendix A. These standards specify DAA system characteristics that should be useful for designers, manufacturers, installers and users of the equipment.
These MOPS focus on Unmanned Aircraft (UA) to enable safe flight in airspace normally frequented by commercial transport and general aviation aircraft. Aircraft operations in all classes of airspace vary, from operation under Instrument Flight Rules (IFR) in Reduced Vertical Separation Minimum (RVSM) airspace to VFR operations with minimal onboard equipage. The UA may need to carry relatively large and high-power sensor systems, depending on the class of sensors required for the speed of the UA. Alternatively, these MOPS also allow a class of equipment where all sensors are on the ground, which enables operations of UAS with reduced payload capabilities (see Subparagraph 22.214.171.124 for descriptions of all equipment classes). This version of the document adds a class of non-cooperative sensor that does allow some weight and power savings. Future revisions of this document may address other operational scenarios and sensors better suited to smaller UAS needs, pending further negotiation with airspace regulators.
During the original development of this document, members of the committee expressed concern about equipment without an explicit collision avoidance function providing an appropriate level of safety for the in-scope operations. Concerns were expressed regarding the safety of the system when compared to manned see-and-avoid capability, the usability of the well clear definition developed herein, and the impacts of replacing "collision avoidance" with a "regain well clear" concept. Concerns were also expressed that a formal safety analysis was not available to guide MOPS development, and that a top-level performance requirement was not established to provide a means for requirement traceability to lower-level requirements. To this end, the Federal Aviation Administration (FAA) commissioned an internal Safety Risk Management Panel during development of RTCA Document 365 (DO-365) to analyze and identify the conditions under which Equipment Class 1 or Equipment Class 2 is sufficient for the intended operations in the National Airspace System (NAS) (see Subparagraph 126.96.36.199 for a description of equipment classes). The FAA is using this safety analysis to determine required equipage and any necessary operational mitigations. Going forward, the committee expects the FAA to update the safety analysis based on changes to DAA systems or the NAS.
Compliance with these standards is recommended as one means of assuring that the equipment will perform its intended function(s) satisfactorily under the conditions specified herein. Any regulatory application of this document is the sole responsibility of appropriate governmental agencies.