ATC separation assurance for RPASS and conventional aircraft in en-route airspace

Abstract

Remotely-piloted aircraft systems (RPASs) present interesting and complex challenges for air traffic management. One of the most critical aspects of the integration of RPASs in non-segregated airspace is safety assessments. This paper lays out a methodology for estimating the minimum protection distance (MPD) that is required to avoid potential conflicts between RPASs and conventional aircraft. The MPD determines the final moment that air traffic control may instruct a RPAS to start climbing with a fixed rate of climb (ROC) to avoid separation minima infringement. The methodology sets out a conflict-resolution algorithm to estimate the MPD. It also models the impact of communication, navigation, and surveillance requirements on the MPD. The main difference between RPASs and conventional aircraft is that the former needs additional communication between the RPAS and pilot in the form of a required Comand and Control link performance (RLP). Finally, the authors carried out Monte Carlo simulations to estimate the value of the MPD only for the head-on encounter, which is the worst scenario. The results showed that the main factors affecting the MPD were RLP and ROC. By increasing RLP and decreasing ROC it was possible to reduce the MPD from 28 to 17 nautical miles; however, the variation in the MPD was not linear.