On the occasion of the publication of a first EASA draft regulatory framework regarding the operation of air cabs in cities (NPA 2022-06), AviaCert provides a brief overview of further challenges in the context of the realization of Urban Air Mobility (UAM).
Although helicopter cabs were already operating in New York City between the Pan Am Building in Manhattan and JFK Airport in the 1950s, the idea of taxi-like shuttle services via aircraft has been given a new boost by technological progress in the 21st century. Electric Vertical Take-Off and Landing aircrafts (eVTOLs) are expected to form the basis for a quiet, safe, efficient and sustainable urban air transportation system of the future.
More than 700 different design variants from almost 350 companies and innovators already exist for eVTOLs intended for passenger transport - and the trend is rising. According to EASA SC-VTOL, they are classified in the "Enhanced" certification category, which requires an extensive approval procedure. The safety standard to be met for eVTOLs is deliberately set in the same order of magnitude as for conventional airliners (EASA SC-25): The average probability per flight hour of a catastrophic accident must not be greater than 10-9. Despite this standard, passenger safety concerns - in terms of both safety and security - together with noise emissions are the most frequently cited concerns in surveys regarding the implementation of UAM. However, with regard to the social acceptance of this new mode of transportation, a positive trend can be observed due to the increasing presence in the media, numerous research projects and studies, and the presence at exhibitions and trade fairs.
Another challenge for the efficient and profitable operation of eVTOLs is the establishment of an infrastructure that meets their needs. This includes, in particular, suitable take-off and landing areas with appropriate technical facilities and resources for turnaround, maintenance, repair and overhaul, the so-called vertiports. EASA has already published an initial guideline (PTS-VPT-DSN) regarding the technical specifications for these. This is part of a regulatory framework for vertiport design, certification, operation and oversight (RMT.0230) that is currently under development. Although existing heliport or airfield infrastructure can still be used for initial air cab operations, additional takeoff and landing facilities will be needed as UAM networks expand and densify, particularly in the center of urban areas. In contrast to conventional heliports, vertiports are characterized primarily by modified obstacle limitation areas, lower noise emission limits, and a charging infrastructure for eVTOLs that must be provided. Extensive planning and/or feasibility studies are required in advance for the development of a demand-oriented vertiport infrastructure. As flight operation areas, vertiports also require certification and approval by the relevant aviation authority.
The integration of aircraft into urban airspace also poses challenges, especially for the existing air traffic management system. The proximity of UAM operations to major international airports and the resulting aircraft movements within control zones, as well as the increasing volume of drones in lower airspace, would quickly push air traffic controllers to or beyond their capacity limits. With the goal of safe, efficient and equitable integration of all users of lower airspace, UAM flights should also be served by a UAS Traffic Management (UTM) system in the future. Although air cabs will operate autonomously in perspective, it is expected that they will initially be piloted by pilot:ins and fly under visual flight rules (VFR) during the initial phases of operation. As a result, solutions must be identified or developed, particularly with regard to communication between the aircraft as well as separation and possible conflict situations.
Leading eVTOL manufacturers such as Joby Aviation or Volocopter are planning to launch their commercial flights as early as 2024. Until then, the challenges mentioned above have to be overcome, a regulatory framework has to be defined and implemented, and the technological requirements have to be met. However, challenges and obstacles have always been an opportunity for change and progress in the history of aviation.
With two decades of aviation experience and interdisciplinary teams, AviaCert has the necessary competencies to develop concepts of operations (ConOps) for vertiports, to support companies in certifying and approving vertiports, and to conduct feasibility studies in the field of UAM. In addition, AviaCert offers extensive expertise in the areas of aviation law, compliance and certification, flight operational safety, and training and qualification.