With the advancement of next-generation communication technologies, urban air mobility (UAM) is rapidly emerging as an alternative mode of transportation alongside traditional ground-based transportation. Furthermore, the development of future air mobility service platforms, including Regional Air Mobility (RAM) for inter-regional travel, is currently in progress. To transition ground-based transportation systems into aviation mobility, it is essential to integrate a wide range of technologies, regulations, and guidelines, not only for physical infrastructure such as ground control centers and vertiports but also for aircraft manufacturing and operation. The urban operating environment for urban air operations must include capabilities for safe and efficient operation. This urban air operating environment encompasses the secure operation of physical elements like aircraft, vertiports, and air traffic control centers, as well as the operation of information security technologies in the cyber domain. The operational data of Advanced Air Mobility (AAM) service platforms is becoming increasingly reliant on communication technologies, and a high level of dependence, making effective cybersecurity measures essential, as cyber threats can directly impact safety. Aircraft, vertiports, and air traffic control centers must ensure safety and reliability in the physical domain while establishing a trustworthy information exchange system in the cyber domain. Implementing robust cybersecurity protocols and operating technologies capable of identifying and responding to potential threats are also required. However, potential threats exist, including interference from ground-based operations, disruptions, exposure of aviation-related information (CSNi), interception, tampering, and theft. Current UAM operational systems face vulnerabilities in management and operation, such as unauthorized use by non-permitted individuals, involving UAM aircraft, UAM pilots, Air Traffic Control (ATC) systems, operators, vertiports, and vertiport operators. Therefore, this paper aims to propose a trustworthy operational structure for AAM operators as a response to security requirements for securing safe and operational AAM and addressing potential cyber threats.