AN EXPERIMENTAL EVALUATION OF A GNSS+AIDED COURSE GUIDANCE TECHNIQUE FOR GENERAL AVIATION

Abstract

This paper presents an experimental evaluation of course guidance technique that uses the aircraft's velocity vector to assist the general aviation pilot in following a course. This velocity vector-based approach to course guidance greatly simplifies the pilot's task of maintaining a desired track, especially in the presence of wind. Until recently, such guidance has been solely available to transport-category aircraft using expensive inertial reference systems, and the accuracy of other available navigation systems have not been suitable to derive an aircraft's velocity vector for guidance applications. Emerging technologies such as the Global Navigation Satellite System (GNSS), however, offer the capability to derive an aircraft's velocity vector, along with several other useful navigation parameters, at a reasonable and justifiable cost. Two types of GNSS-based course guidance displays are presented, and a piloted simulation experiment to evaluate the algorithm and displays is described. In this experiment, pilots executed a series of 20 minute flights culminating in a holding pattern and a VOR approach. In some of the flights the pilots used traditional radio navigation instruments, and in others they used variations of the GNSS-aided displays. Results indicate that pilot navigation performance improved significantly when using the GNSSaided displays, and that many mental errors associated with traditional VOR-based navigation were largely eliminated. Several specific guidance display features were also evaluated for usefulness and for impact on pilot performance.