VTOL Aircraft Terminal Area Operations Research

Routine all-weather operation of VTOL aircraft in the terminal area environment is not possible at the present time because of the lack of knowledge required for satisfactory operation of this type of aircraft under IFR conditions. Specifically, many operating problems have been encountered during operation of VTOL aircraft in transition flight at low speed on an approach guidance system. This paper briefly summarizes these problems and then discusses related results that have been obtained from several flight research investigations. Included will be discussions of the instrument approach techniques, methods of glide path and speed control, aircraft handling characteristics, time fuel airspace requirements, and pilot displays.