Remotely piloted aircraft systems (RPAS), when operated beyond visual line of sight, are usually affected by considerable signal transmission time delays. It is known that time delays reduce the stability margins of a control loop and can cause instability, also when the loop is closed by a human operator. Hence, time delays are avoided in (manual) flight control. For RPAS, this means that landing as a high precision tracking task is usually accomplished either by a local pilot who is confronted with only negligible time delay, or by an automatic landing system. While the first strategy requires a local pilot, the second requires an intact guidance and navigation infrastructure. This paper presents and compares alternative strategies for remotely controlled landing through communication links with round trip time delays as high as several seconds. The analyses indicate that higher-level maneuver demand systems and open-loop piloting techniques may provide adequate handling qualities at the cost of potentially long landing distances or increased vehicle weight.     «

Remotely piloted aircraft systems (RPAS), when operated beyond visual line of sight, are usually affected by considerable signal transmission time delays. It is known that time delays reduce the stability margins of a control loop and can cause instability, also when the loop is closed by a human operator. Hence, time delays are avoided in (manual) flight control. For RPAS, this means that landing as a high precision tracking task is usually accomplished either by a local pilot who is confronted...     »