USTETA eVTOL Article Draft
The idea of leaving city traffic behind has been a recurring theme in futurism since the drivers first experienced the aggravations of gridlock. Fortunately for commuters, it seems that in the next decade readily accessible, automated aerial transit will become a reality. The promise of electric vertical take-off and landing (eVTOL) systems to allow for decentralized, economical aerial transport in urban areas is hard to overstate. Indeed, urban air mobility (UAM) is poised to become an increasingly important transportation sector. Companies like Uber have made significant inroads regarding the development of both eVTOL airframes and the infrastructure needed to support them. In general, the plan is for the systems to be entirely automated in the interest of maximizing passenger capacity and minimizing overhead costs. However, before we can truly realize the dream of democratizing flight, there are several key factors which must be ironed out.
The first critical factor is noise. This might seem a little counterintuitive, considering eVTOLS rely on electric motors for propulsion; we all know how quiet electric cars are. The fundamental difference is, instead of using the electric motor to turn wheels (a generally low-noise operation), eVTOLs are turning rotors at hundreds of miles per hour in order to generate lift. This creates sound, and lots of it. Unlike commercial jets, which generally fly at a high-enough altitude to mitigate the noise generated by turbofans, eVTOLs flying in a UAM configuration are going to be at a much lower altitude over densely populated areas. Thus, reducing noise is a major concern for eVTOL UAM operations. Some experts believe that a 15db reduction compared to existing rotorcraft platforms is the bare minimum for eVTOL UAM to be accepted by the public and regulators. Certain design elements, like keeping rotor tip speeds low and reducing disc loading by reducing the ratio of weight to the total rotor area, can help make this a reality. Advanced modelling can also tailor operations based on the time of day to minimize disturbances.
The noise level isn’t the only way that acoustics affect the implementation of eVTOL UAM, though. The character of the noise is equally important. The better it blends into the prevailing ambient noise level, the lower the likelihood of noise becoming a public nuisance. There is a psychoacoustic component to this as well. If the public associates eVTOL noise with practical, accessible transportation, they will be far more accepting of any increased noise level than if eVTOL operations are only used by the rich to make trips to the golf course.
The next key consideration for eVTOL UAM success is infrastructure and communication. Some propose that initial eVTOL UAM operations will be based out of existing airports to avoid relying on the construction of vertiports as operations are in their initial stage. While this makes sense from an initial cost standpoint, it presents a new issue: air traffic control.In order for safe operations in heavily trafficked airspace, automated systems will need to be able to reliably and quickly respond to queries and commands from air traffic controllers, as well as communicating their position with other aircraft. This requires the implementation of a comprehensive, universal communication standard resulting from close cooperation between industry and regulators.
Operating from smaller, decentralized vertiports would avoid the issue of the airspace around airports, but with increased upfront costs and financial risk as this infrastructure would need to be built before eVTOL UAM service could begin. Regardless, vehicle-to-vehicle (V2V) communications and sensor suites would need to robust in order to avoid accidents. Additionally, small vertiports may require queuing in order to support larger numbers of passengers, further emphasizing the importance of comprehensive command-and-control.
The final important consideration for general eVTOL UAM operation is weather. While eVTOLs conducting UAM operations likely wouldn’t be flying high enough for icing to be a concern in all but the most extreme conditions, accurate and timely weather reporting is critical for safety. Should icing occur, the automated systems must be able to respond quickly as icing can have effects on rotorcraft that are quite hard to counter, including differential icing of rotors. The risks of extreme weather are magnified in the crowded skyline of an urban environment, as low altitude eVTOLs must be able to avoid crashing into structures. Integrating weather reporting into command-and-control networks is a requirement in order to safely land automated eVTOLs when weather becomes too hazardous to fly in.
Fortunately, there is significant effort being devoted to overcoming these obstacles to commercial automated eVTOL UAM transportation, with pioneers in the field looking to reap the benefits of revolutionizing urban transit. Morgan Stanley predicts that the autonomous UAM market could be worth as much as $1.5 trillion by the year 2040, with thousands of airframes carrying passengers worldwide. The first companies able to successfully navigate the engineering and regulatory pathways leading to the deployment of practical eVTOL UAM systems will have a major advantage over their competitors. The future certainly looks bright for this industry!