Detect and Avoid Systems: Ready for Takeoff with DO-365B


Recently, the Minimum Operating Performance Standards (MOPS) for Phase 2 of the Detect and Avoid (DAA) development initiative were approved by RTCA. Most notably, the RTCA’s new DAA DO-365B MOPS incorporates the recent release of Airborne Collision Avoidance System (ACAS) Xu MOPS.

For the first time, technology now standards exist to enable unmanned aircraft to take off and land from almost any class of airspace, greatly opening the skies to BVLOS flight for UAS with a compliant, certifiable DAA system on board.

This is huge news! We’re breaking down what it means to the industry here:


  1. What is DO-365B? From the RTCA:The Detect and Avoid (DAA) system was specified to assist the remote pilot with operating an aircraft safely in the NAS. All aircraft flying in the NAS must comply with the operating rules of 14 CFR, specifically, §§ 91.3, 91.111, 91.113, 91.123 and 91.181(b), which address see and avoid, collision avoidance, right of way rules, and remaining well clear. The DAA equipment may also be used to comply with the duties in International Civil Aviation Organization (ICAO) Annex 2 to the Convention on International Civil Aviation, specifically Chapter 2, Paragraph 2.3.1. These operating regulations assumed that a pilot would be onboard the aircraft and would be able to fully comply with these rules. This document contains MOPS for DAA systems used in unmanned aircraft transiting and performing extended operations in Class D, E, and G airspace along with transiting Class B and C airspace. It includes equipment to enable UAS operations near Terminal Areas during approach and departure in Class C, D, E, and G airspace, and off airport locations, but not operating in the visual traffic pattern or on the surface. It does not apply to small UAS (under 55 pounds (lbs.)) operating in low level environments (below 400′) or other segmented areas. This revision Added Class 3 – ACAS Xu, Non-cooperative [DAA Well Clear] (DWC) applicable to all classes, updated ATAR classes for different performance levels. Purchase your copy of the standards here.

  3. What does it mean? Simply put, it means that the standards are now in place for detect and avoid technologies that will enable takeoff, BVLOS operation in the national airspace system (NAS), and landing from anywhere EXCEPT a large airport.
    Imagine it! For example:
    – freight companies can keep fleets of drones at non-towered airports, taking off in Class D and G airspace for last-mile delivery
    – companies that perform long linear inspections, such as pipelines or railroads, can keep fleets of drones near their facilities and be approved to takeoff, fly BVLOS, transit Class B airspace, and land
    No more hassle in trucking drones to an approved location obtained by waiver.
    No more restrictions to flying just in special-purpose airspace.

    In short, with DAA technology on board, built to DO-365B specifications (such as Sagetech’s detect and avoid solutions), companies can now realize the vision of drone BVLOS flight. Now that the standards are in place, the FAA can create the final TSO requirements. The TSO for DAA systems is anticipated to be TSO-C211a.

    (To see how companies are already starting their BVLOS journey with DAA equipment, read our story on how American Aerospace, NASA, and Sagetech performed a recent pipeline inspection demo.)


  1. What is included in a Detect and Avoid System? As defined by the DO-365B MOPS, the technology functionality requirements include an ACAS Xu computer with interrogator functionality, an ADS-B transponder to communicate with cooperative aircraft in the NAS, a non-cooperative traffic sensor (such as a certified radar system), and a C2 link. Sagetech is using its microelectronics expertise to package this system right now in a low SWaP DAA system, purpose-built for UAS, that will undergo test flights by the end of the year.


    1. What is next? Phases 1 and 2 of the Detect and Avoid MOPS initiative are now complete. Phase 3 is up next, where standards for DAA systems will be created and defined as ACAS Xr (manned and unmanned rotorcraft) and ACAS sXu (small drones < 55 lbs.).




DAA Phase 3 – ACAS XR & SXU

Focused on civil UAS equipped to operate into Class A airspace under IFR flight rules

1.      Transitioning of a UAS to and from Class A or special use airspace

2.      Traversing Class D, E, and G airspace

Extends the Operational Environment

1.      Extended UAS operation in Class D, E, and G airspace

2.      Take-off and landing operations in Class C, D, E and G airspace

3.      Transit through Class B airspace

Expand the supported operations of DAA equipment to address use cases that are applicable to smaller UAS as well as more specialized UAS

1.      High Altitude Pseudo-Satellite launch and recovery operations

2.      Smaller UAS platforms with more limited performance and operations closer to terrain/obstacles

3.      VTOL operations including Advanced Air Mobility (AAM)

4.      Part 135 cargo operations


Please visit Sagetech’s Detect and Avoid solution page for more information or to contact us about integrating our DAA system on your UAS.