As the world’s population continues to increase, many of these people will gravitate towards city living, with one estimate from the UN stating that 60% of the global populace will be urban by 2030. This in turn will continue to put significant strain on road networks and other ground-based infrastructure, increasing commute times as well as emissions.
Urban Air Mobility (UAM) is an up-and-coming concept that will shift some of this urban road traffic to the skies, using small aerial vehicles as “air taxis” as well as flying delivery platforms. These vehicles are likely to be electric VTOL (vertical takeoff and landing) aircraft, which will help lower the carbon footprint of transport networks, especially if the electricity is sourced sustainably. Once UAM networks are established and economies of scale kick in, the use of electric VTOLs should also be cheaper than existing platforms such as helicopters.
Dozens of different eVTOL designs are currently under development by OEMs around the world. These can be grouped generally into three different types:
The aircraft’s tiltable thrusters are used both for lifting and cruising, and the design also uses wings to provide additional lift for forward flight. This makes it highly efficient and provides the fastest cruising speeds, at the cost of increased complexity and weight.
Pure rotary operation with no wings, like a giant multirotor drone. Provides a high level of redundancy and outputs less noise than a helicopter but is the slowest and least efficient option.
Lift and Cruise
A hybrid solution, with independent propulsion systems used for lifting and for cruising. This provides the benefits of redundancy, with an efficiency level in between the other two options.
During the initial establishing phases of Urban Air Mobility (UAM), a pilot-in-command (PIC) will most likely be located physically on board the aircraft. but most of the future visions of this new concept will see eventual shifts towards remote piloting and then to autonomous unmanned aircraft. The development of UAM thus shares many of the same issues and challenges as the commercial drone industry is currently undergoing during its transition to BVLOS.
Social and Technical Issues in Urban Air Mobility
According to surveys performed by Airbus and by the EASA (European Union Aviation Safety Agency), noise and safety are two of the leading concerns that stand in the way of mass acceptance of Urban Air Mobility (UAM) in cities around the world.
The potential noise levels of regular UAM operations are still being characterized and studied. Early studies suggest that acceptance of vehicle noise may increase over time as it becomes part of the familiar city soundscape. Distance, duration, and repetition all play a part in how unpalatable the noise is to pedestrians and urban dwellers, and UAM operations will have to be planned with these in mind.
As with all aviation matters, safety will be paramount in making widespread UAM a reality. According to the aforementioned Airbus survey, many people see rotary aircraft as inherently less safe than those with wings. Autonomous vehicles have also taken a publicity hit in recent times, due to incidents within the self-driving car industry. Extremely strict safety margins will therefore be essential for a high level of acceptance of the new technology, especially once UAM services move away from onboard piloted operations.
UAM operations will also have to be introduced relatively slowly, and in stages. The United States FAA (Federal Aviation Administration) has published a CONOPS (Concept of Operations) detailing how this might be done.
According to the CONOPS, the very first UAM operations will take place within current helicopter infrastructure, utilizing existing routes and helipads. Pilots will be onboard, and no additional regulations or procedures will need to be put in place.
The next stage will see UAM operations expand to specially designated flight corridors. These corridors will link two known aerodromes and allow new technologies and aspects of the system such as detect-and-avoid and strategic deconfliction to be tested.
As technologies and procedures mature, UAM will then eventually expand to more complex operations, with potential for remote piloting and enhanced levels of automation. Significant regulatory change will be required to support operations at this level.
Critical communications for Urban Air Mobility (UAM)
At all stages of development, UAM will require a variety of different types of data to be communicated between the eVTOL aircraft and the ground control stations and other aircraft. These include:
– Control signals, telemetry, and vehicle health information
– ATC (air traffic control) communications
– Situational awareness information to be communicated to UTM (unmanned traffic management) networks and to other aircraft in the vicinity
– Flight plans, as well as any potential deviations due to weather, equipment failure or other factors
– Real-time video for navigation and detect-and-avoid purposes
As we have discussed, UAM is a highly safety-critical endeavor, meaning that the communications system in the eVTOL aircraft must have as close to 100% availability as possible.
Satellite communications (SATCOM) terminals are usually too bulky for smaller drones, but the large size of UAM vehicles means that this is no longer a factor. While latency can be an issue, SATCOM may well be viable for non-time-critical data transfer.
Cellular communications, particularly 5G, provide several advantages for UAM. 5G delivers extremely low latency, making it ideal for functions such as remote piloting C2 (command and control) and communications with ATC and UTM. It also provides the bandwidth necessary for real-time video streaming.
While taking advantage of the highest 5G performance requires closer proximity to cell towers than its predecessors, this is less of a disadvantage for the UAM use case, as the operations are primarily intended to serve cities and built-up areas where the density of cell towers is much higher.
Trials are currently under way in Singapore to test the viability and performance of 5G communications for UAM, including unmanned operations. These trials will initially take place along Singapore’s coast, with plans to expand further inland.
Halo – the enabler for next-generation air taxi and delivery services
Elsight’s Halo is an ideal platform for OEMs and developers to test new UAM platforms and proof of concepts. Powered by advanced cellular bonding technology, it aggregates up to four IP links from different carriers into one robust datalink, providing critical redundancy for the utmost in safety and reliability, as well as powerful bandwidth management. The 5G-capable Halo is also fully compliant with the FAA and EASA Remote ID requirements, futureproofing it for next-generation aviation solutions.
To find out more about how Halo can help you to develop your UAM platform, please get in touch !