National Campaign (NC)-1 Strategic Conflict Management Simulation (X4) Community Based Rules

Projected demand for transportation services in the urban environment has led to the development of several Concepts of
Operation for Urban Air Mobility, or UAM. UAM is a concept for the transportation of people and goods in the metropolitan
environment using small, efficient aircraft over short distances as part of an expanding multimodal transportation network. UAM
will leverage emerging technologies including electric Vertical Takeoff and Landing (eVTOL) aircraft, increasing levels of
automation and a new operational paradigm in dense airspace where a set of agreed-upon rules govern the procedures and
interactions defining a cooperative environment in which operators are entrusted with a range of functions typically conducted by
Air Traffic Control (ATC). These rules, proposed in the FAA NextGen Office’s UAM Concept of Operations [1], were originally
termed Community Based Rules or Community Business Rules (CBRs), and will in the future termed Cooperative Operating
Practices (COPs); this document uses the original term, CBR.

CBRs are a set of rules, developed by the UAM community and (where necessary) approved by the FAA that govern the
interactions between UAM entities and limit the need for ATC services including, but not limited to, separation control by ATC,
addressing a fundamental challenge to scaling UAM operations. UAM community development of CBRs is anticipated to
accelerate the adoption of new practices while retaining the regulatory authority of the FAA within required domains (e.g., NAS
safety, security and equal access). However, there currently exists no agreed industry forum or defined procedures for CBR
development. Investigation of best practices for the development of UAM CBRs was identified by NASA and the FAA NextGen
Office as a research need.

In collaboration with seven industry partners, NASA participated in a series of simulations that investigated elements of the
envisioned UAM operations, with a primary focus on Strategic Conflict Management (SCM). The development and conduct of
cooperative UAM simulations with seven industry partners provided a unique opportunity to investigate CBR development
practices. Development of CBRs for the UAM SCM simulations was conducted in parallel with simulation capability
development and was closely related to requirements definition for the simulations. As such, the CBR development effort
presented herein had two objectives: explore CBR development practices in collaboration with the industry partners and develop
an initial set of UAM CBRs to support simulation requirements definition and development.

Consensus was achieved among NASA and the industry partners on 24 CBRs that were developed to support the cooperative
simulation operations across five topic areas: General (related to test requirements), Operational Intent, Conformance Monitoring,
Demand Capacity Balancing, and Airspace Constraint Management. Additional topic areas and CBRs were discussed but were
deemed outside the scope of the simulation; these are included in the appendices.

A collaborative, iterative process was employed for developing the CBRs engaging both NASA and Industry; because CBR
development is envisioned to be community-driven, opportunities were sought that provided industry partners leadership roles in
developing CBRs. The following key observations and recommendations may aid the UAM industry in future CBR development
efforts:

- The lack of a defined process proved challenging initially. Stakeholder engagement in the early stages of CBR development was intermittent and may have been due to the lack of a clear definition of roles and responsibilities of those involved in the effort.
- Industry leadership of CBR topic areas proved successful. Discussions in these topic areas were engaging, with alternate viewpoints freely discussed and detailed CBRs resulting. This points to the importance of identifying the best-suited leadership in technical areas for CBR development.
- Discussions within a CBR topic area were typically dominated by only a few participants. Whereas all industry partners contributed to CBR development, within each topic area, technical leadership was evident even when not formally established. This observation may indicate that smaller, focused groups may be more effective in initial CBR development than an open forum or large standards development effort (although both maybe required prior to FAA review and approval for some CBRs).
- Identifying suitable forums for initial UAM CBR development and identifying the most effective industry participants and leadership will be crucial for successful CBR development. Although the operational need for UAM CBRs may not be immediate, establishing the forums and leadership to define the processes for CBR development is a prudent early step to UAM realization.