FAA's New Urban Air Mobility ConOps Raises Questions

 - July 15, 2020, 2:38 AM
FAA's Concept of Operations for Urban Air Mobility is intended to map out how new eVTOL aircraft will share airspace with other users. [Image: FAA]

In his cover letter accompanying the FAA’s first version of the concept of operations (ConOps) for Urban Air Mobility (UAM), Steve Bradford, the agency’s chief scientist for architecture and NextGen development, admits that the document is a “work in progress.” Given the content and the reaction to it, that perhaps is an understatement.

The ConOps 1.0 document was released July 1 and follows discussions with the industry in 2019. While industry observers and stakeholders are universally supportive that the initiative is at last in motion, not everyone is happy on its direction. 

ConOps establishes the concept of morphing existing VFR helicopter corridors into dedicated air lanes for passenger and freight eVTOLs without ATC services, governed by “community business rules.” And with “demand capacity balancing” skewed to “performance-based” service providers (PSU—a provider of service for UAM), it has triggered a flurry of practical operational questions.

Chief among them is how all this gets integrated into the National Airspace System while maintaining current safety standards, how to ensure fair access to the dedicated airspace, and how not to alienate local governments and citizen groups while at the same time satisfying the FAA’s institutional need to enshrine preemption. 

So far, perhaps no one has aired more skepticism than Anna Dietrich, co-founder of eVTOL aircraft developer Terrafugia and the current co-executive director of the community air mobility initiative (CAMI). “While I can appreciate some of the challenges that this ConOps is attempting to address, I can’t help but think that it’s heading down a path that will be detrimental to both the UAM industry and the communities it intends to serve,” she commented in her personal blog on July 6.

Among other things, Dietrich faulted the ConOps for failing to articulate how UAM corridors would be protected from “non-cooperative traffic,” for effectively privatizing the UAM corridors thereby limiting access to the highest payers, and for potentially endangering safety. 

Much, but not all, of what is contained in the ConOps was previewed in a 2019 Mitre Corp. study entitled, “Urban Air Mobility Airspace Integration Concepts.” Mitre stressed the need to integrate UAM into the U.S. National Airspace System using “existing procedural concepts” while minimizing any additional load on ATC services.

Like the ConOps, which has suggested UAM corridors with expandable boundaries based on traffic volume and flow, Mitre proposed using “dynamic delegated corridors” (DDCs) which can be opened and closed over time, depending on weather, traffic volume, airport runway configurations, and legacy air traffic. The DDCs are designed with input from a wide variety of stakeholders and its boundaries are digitally communicated and change over time.  Also, like the ConOps, Mitre envisions a system that favors more technologically advanced, “performance-based” UAM vehicles for slotting into the most direct routes. 

But as currently written, some critics say the ConOps has the potential to spawn UAM into a disjointed quilt of nonstandard rules and regulations crafted by disjointed fiefdoms. As envisioned, the system will be a series of corridors, each connecting two specific landing sites.

To operate on a specific corridor, aircraft must meet performance standards specific to that individual corridor, standards set local stakeholders via the community business rulemaking process. And the performance standards on an individual corridor can change based on traffic level—with FAA approval. To deploy a UAM aircraft on multiple corridors, an operator would need to equip it to the highest standard within a given service area and that standard is potentially dynamic. 

However, the FAA stressed the ConOps document will be revised and that, when UAM vehicles enter service, the process will be grounded in the agency’s traditional incrementalism. The ConOps noted, “UAM implementation is an evolutionary developmental approach starting with low-complexity, low-operational tempo operations and building toward an environment of higher operational tempo and the introduction of UAM airspace structure to mitigate an otherwise higher level of complexity.”

The FAA has promised a good deal more of “analysis, simulation, demonstration, and community engagement” before UAM will “mature to encompass increasingly complex operations in heavily populated environments and more heavily utilized airspace.” And one of the next steps to that end is likely to be the publication of a ConOps 2.0 version at an as-yet-unspecified date.