ABSTRACT
The main priority of 4D ATM, as defined within PHARE, is the increase of airspace capacity, subject to the overriding requirement for system safety. An airborne flight management system could be an important source of accurate, timely information on aircraft intentions for ATC. This study designed and evaluated a prototype FMS interface, based on the navigation display and incorporating enhanced functionality. The interface allows graphically-presented routes to be modified directly on the display using a trackball as a cursor control device. Pilots judged this direct manipulation a very intuitive method. The trackball was rated suitable, even under turbulent conditions. When modifying a route, a pencil analogy was preferred to a rubber band analogy.
