Investigation of certification processes of electric vertical take-off and landing aircraft in terms of ai̇rworthiness: Comparison of FAA and EASA applications

Population density in big cities is increasing day by day. This increase brings infrastructure inadequacies and traffic congestion. Due to traffic congestion, people living in megacities spend a significant portion of their days on the roads, such as 3 to 7 hours. Investments in road and rail systems to solve such a problem are not only very costly but also inadequate at some points. On the other hand, urban taxi transportation represents a $400 billion market globally and offers an important market opportunity for alternative modes of transportation. Therefore, "Urban Air Mobility" is expected to come to the forefront in the near future. Urban air mobility encompasses all types of aircraft used in urban air transportation, from traditional rotary wing aircraft to small delivery drones and state-of-the-art electric vertical take-off and landing aircraft. The aviation sector, which lies at the heart of all innovations, has recently experienced significant technological developments, especially in order to minimize the effects of climate change. With the development of battery technology, the use of electric motors has come to the forefront and a new class of aircraft has emerged thanks to developments such as autonomous driving systems and 5G. Electric vertical take-off and landing aircraft (EVTOL) are electric aircraft designed to carry passengers or cargo within cities and between cities in close proximity. From large companies such as Airbus, Uber, Joby Aviation, Archier, Lilium, EHang to small startups, around 250 EVTOL projects have been produced. One of the biggest obstacles to the safe daily use of these projects is certification. The certification of an aircraft consists of two main intertwined processes: type certification and airworthiness certification. Type certificate refers to the certificate issued to an aircraft type in general, starting with the approval of the design organization. Airworthiness certification refers to the process that is repeated for each aircraft after the approval of the production organization and ends with the registration of the aircraft. The aim of the study is to address the standards developed by FAA and EASA for the airworthiness of EVTOL vehicles. In this context, a comparative analysis was carried out by examining the data in the publicly available sources of the relevant organizations and the literature. First of all, the studies in this field were accessed through a literature review and then the documents and reports published by the International Civil Aviation Organization (ICAO), National Aeronautics and Space Administration (NASA), Federal Aviation Administration (FAA), European Aviation Safety Agency (EASA) were examined. Considering the approaches of both authorities, EASA has basically chosen the method of publishing a draft document, evaluating the suggestions and criticisms received and creating new and improved documents. FAA, on the other hand, published documents based on its long-established practices and made modifications for new technologies.