With the rapid development of emerging aerial vehicles such as Unmanned Aircraft Systems (UASs) and electric Vertical Take-Off and Landing (eVTOL) aircraft, new concepts and systems for low-altitude operations, represented by Advanced Air Mobility (AAM) and UAS Traffic Management (UTM), pose unprecedented challenges to the low-altitude safety management capabilities of existing aviation systems. The future of low-altitude operations is expected to evolve towards high-density, on-demand responsiveness, and collaborative operations between manned and unmanned vehicles. In this context, traditional management approaches within the human-in-the-loop framework are inadequate to meet the airspace demands of low-altitude operations, necessitating development of a more timely and intelligent risk management capability supported by low-altitude air navigation systems. This paper first elucidates the fundamental concepts of low-altitude safety and proposes a safety management framework for future low-altitude operations, clearly defining the roles and responsibilities of various stakeholders. In response to the in-time and intelligent capability requirements for risk management in aviation systems driven by the development of the low-altitude economy, this paper reviews the evolution of risk management technologies and capabilities in aviation systems, synthesizes the current developmental demands, and outlines the representative research, current status, and limitations of key technologies. Based on existing gaps and present demands, this paper identifies core challenges faced by low-altitude aviation systems and proposes future directions for developing real-time risk management capabilities. Finally, to promote the safe and orderly development of low-altitude operation, this paper concludes by outlining the core challenges faced by low-altitude air navigation systems and providing directions for future development in constructing real-time risk management capabilities, offering guidance for research and construction of low-altitude air navigation system risk management capabilities.

The successful application of new technologies such as remotely piloted aircraft systems, distributed electric propulsion systems, and automatic control systems on electric vertical take-off and landing(eVTOL) aircraft has prompted Urban Air Mobility (UAM) to be mentioned frequently. UAM is a newly raised transport mode of using eVTOL aircraft to transport people and cargo in urban areas, which is thought to share some of the traffic on the ground. One of the prerequisites for UAM to operate on a regular basis is that its demand can support the operating costs, so forecasting UAM demand is necessary. We conduct UAM demand forecasting based on the four-step method, focusing on improving the third-step modal split, and propose a demand forecasting model based on the logit model. The model combines a nested logit (NL) model with a multinomial logit (MNL) model to solve the problem of non-existent UAM sharing rates. We use Chengdu, China as an example, and focus on forecasting the UAM traffic demand in 2030 with the help of the four-step method. The results show that UAM is suitable for shared operation during the early stages. With a fully shared operation, the UAM share rate increases by 0.73% for every kilometer increase in distance. Moreover, UAM is more competitive than other modes for delivery distances exceeding 15 ​km. Finally, using the distributions of the share rate and traffic flow pattern from the simulation, we propose the routes that can be prioritized for UAM operations in Chengdu.