Options for insertion of RPAS into the Air Traffic System

Remotely Piloted Aircraft Systems (RPAS) distinguish from ordinary manned aircraft in that the pilot is not on board the aircraft but somewhere remote. Whatever the manner the remote pilot interacts with the RPA, by way of Command and Control (C2) datalink and any associated level of automation, significant parts of the control loops are performed by computers similarly to high-end manned commercial aircraft. Hence, controlling an RPA using “fly-by-wireless” features is comparable to manned aircraft, as is the typification of hazards. In the high level functional sense, ATC assures separation between individual aircraft movements and the question may be raised what the derived functional requirements would be, knowing that the RPA follows a defined trajectory not really much differently than manned aircraft. Two separation techniques have been discussed in recent research, one “reactive” with the two aircraft observing each other's current state (speed vector and relative geometry) and reacting to an impending loss of separation. The other technique would be “pro-active”, where separation between movements is effectuated on the basis of coordinating aircraft control reference trajectory data. Focusing on the trajectory-based approach, this paper discusses its use as an option for the integration of remotely piloted aircraft systems (RPAS) in nonsegregated airspace, as it could benefit from the results and outcomes from some R&D project conducted since the early 2000s in the frame of the future Air Traffic Management (ATM), i.e. SESAR and NextGen.