The FAA CONOPS (Link) intends to enable Urban Air Mobility operations through corridors in which the aircraft will operate without the direct involvement of Air Traffic Control (ATC). FAA provides an excellent initial road map that presents many opportunities for those original equipment manufacturers (OEM) working in this sector.
Safety is the sum of the robustness of mitigation built on the system, composed of the aircraft, operator, and airspace. The CONOPS strikes a balance among these different actors.
FAA UAM Conops proposes an evolutionary approach to introduce new technology in NAS. Section 3.1 states, "Initial UAM operations are conducted by certified UAM aircraft and conventional helicopters consistent with current rules and regulations." Nevertheless, electrical VTOL has different performances and requirements than a conventional helicopter, requiring further analysis. This analysis should consider uncertainties, such as wind, other aircraft performances/requirements, ground operations, and others. Delays during the airborne phase of flights represent only a minor impact on the overall punctuality / Safety case. In the current operational environment, ground operations gain more relevance. Maintaining excellence on ground operations would allow the different stakeholders to define and maintain a comprehensive 4D aircraft trajectory. Using a reliable and predictable departure time is one of the main tasks of the ground activities. Mutual interdependencies between heliports, as departing delays propagate thought the network, results in system-wide far-reaching effects.
The CONOPS should also clarify if UAM uses current helicopter VFR routes. Also, would this be a VFR operation as most helicopter operations are carried at this moment, or would the CONOPS expand the UAM operations by using the PSU? Then, Part 91 would need to accommodate a new operations class, not only VFR or IFR. The CONOPS should detail this new operation class and clearly defined operational safety objectives. For example, 14 CFR § 91.151 - Fuel requirements for flight in VFR conditions represents a significant challenge for fully electrical propulsive aircraft implementation under current airspace constructs.
Currently, many heliports do not count on Air Traffic Management (ATM) support to organize aircraft flow, and the operations are ad-hoc. Helicopter pilots may communicate or not 15 minutes before arrival to their gate. In highly demand heliports, helicopters may need to hover to land on their gate. This delay would not be an alternative for an e-VTOL aircraft.
Furthermore, the intermodal transportation concept requires a connection between high densely populated areas with international airports; the FAA CONOPS references aerodromes, a general term (refer to section 4.2 of the CONOPS). An airport implies specific regulatory requirements that not all aerodromes may achieve. This CONOPS should then provide more detail on aerodromes' requirements for enabling these UAM operations and international airports' usage, which are significant objectives for intermodal operations. For example, would heliports need adaptation to meet UAM demands? Would these aerodromes require airspace class, type of communication requirements, and implications to PART 91?
CONOPS Sections 3.2 ConOps 1.0 Operations, 3.3 Mature State Operations, and 4.3.3 Pilot in Command (PIC) defines Pilot-in-Command location depending on the maturity level. The CONOPS should then provide more information on regulatory impacts, safety case requirements to achieve a remote PIC, and "provisions for" that would be introduced in nearby operations to mature technology and conduct more automated functions. For example, § 91.3 establishes the role and responsibilities, and § 91.7 states that the PIC is responsible for airworthy aircraft conditions in all flight phases. Then, section 91.7 would require that the PIC have appropriate situational awareness of the vehicle and environmental conditions to continue flying or declaring an emergency. Next, CONOPS iterations should provide further analysis, and FAA interpretation and gaps on operational rules and 14 CFR 1.1 definition such as crewmember.
In section 4.4 UAM Corridors, the corridor permits to introduce aircraft with different performances such as e-VTOL. Then, how would the FAA implement these corridors? For instance, would FAA use special flight rules area (SFRA)?. The SFRA is a region that regulations are modified in whole or in part. Thus, the FAA would adjust airspace classification requirements, altitude, course, speed restrictions, and the like. Then, the corridor definition is crucial since it would allow OEM to meet these requirements. Then, the FAA CONOPS would need to provide more information on:
· Traffic pattern operations
· Approach procedures
· Transit procedures
· Emergency procedures
· Special procedures
· Communication procedures (Frequency, CPDLC)
CONOPS Section 4.8 UAM Operational Assumptions focus on establishing what the FAA/ATC would not do but does not provide critical operational assumptions in this environment. Furthermore, section 4.8 states that "UAM aircraft identification and location information are available to the UAM operator and the PSU Network. ADS-B Out or transponders do not provide this for operations in the UAM Corridor(s); however, other functionality (e.g., UAM applicable Remote ID) may support this identification and location information capability." FAA's concern on ADS-B is well understood, and it should be further detailed in the CONOPS impact on current regulations. For instance, § 91.225 Automatic Dependent Surveillance-Broadcast (ADS-B) Out equipment and use require the use of the ADS-B states that ADS-B Out is mandated since January 2, 2020, for flight in the continental U.S. as follow:
Class A, B, and C airspace;
Class E airspace at or above 10,000 feet MSL, excluding airspace at and below 2,500 feet AGL;
within the Mode C veil;
Above the ceiling and within the lateral boundaries of Class B or Class C airspace up to 10,000 feet;
Class E airspace over the Gulf of Mexico, at and above 3,000 feet MSL, within 12 nm of the U.S. coast.
UAM operations would happen mainly within mode C veil, so removing ADS-B should be further analyzed since it impacts the safety case. Besides, the remote-ID equipage requirement should also be discussed.
Then, CONOPS section 5 states that "This architecture is based on patterns established within the UTM architecture described in the FAA's UTM Concept of Operations." The UTM architecture was established considering only UAS without a human on boards, and safety and the delta should be further analysis since it only provides communication (V2V) communication among aircraft within the boundaries of the corridor but what happens for those aircraft no-participants in the corridor and emergency conditions happened without the possibility of communication (No ADS-B)
Generally, the FAA CONOPS is an excellent first iteration to discover the right questions, frame the problem, and start to bring these operations to reality.
Comentários