Flying Qualities Specifications Framework for Unmanned Aircraft Systems based on Mission Task Elements

Considering the lack of flying qualities specifications of unmanned aircraft systems (UAS), the basic framework of flying qualities specifications based on Mission Task Elements (MTEs) is proposed. Classifications and evaluation objects of UAS in the framework are analyzed by comparing with the characteristics of manned aircraft. As for the construction methods of general framework for UAS flying qualities specification, the three-dimensional classification system, task list descriptions and evaluation methods are discussed. Three-dimensional classification system is proposed based on MTEs, usage and aircraft scale. In addition, task list descriptions are given to explain every task element from classification system. In the aspect of evaluation methods for UAS flying qualities, the objective quantitative evaluation method and subjective criteria evaluation method are discussed. A new modified Cooper-Harper handling qualities rating (HQR) scale for UAS is proposed, which takes the total flight workloads as the index to assess handling qualities, the new workloads proposed synthesize the operator compensation and flight control system (FCS) correction. Furthermore, command response types, airflow effect and pilot induced oscillation (PIO) problems of UAS are discussed, which are investigated by the reference of ADS-33E. This research builds a theoretical foundation and provides a reference for the formulation of flying qualities specifications for UAS.