Ground-simulation investigation of VTOL airworthiness criteria for terminal area operations

Abstract

A two-part ground simulation investigation of variables that affect VTOL terminal area operations was conducted. The baseline vehicle selected was a generalized tilt-rotor aircraft. Experimental variables included the manner in which conversion from airborne to thrust-borne flight is effected, the coupling between conversion and aircraft pitch and heave control, and the allowable range of airspeeds at given thrust inclination angles. Four pilots conducted over 200 piloted evaluations of combinations of these variables for representative VTOL terminal area tasks. Among the results shown are that, for visual approaches, the conversion profile had minimal influence on the aircraft's acceptability but, for instrument approaches, desired performance could be achieved only if all of the conversion was performed prior to acquiring the glide slope, or if additional automation and display assistance was provided.

New vehicle technologies and the next generation airspace system

“…This result suggests that overall passenger throughput at vertiport-enabled airports can be increased with minimal impact on flight delays. Human-in-the-loop simulators have shown that CTR conversion from "turboprop mode" to "helicopter mode" on arrival is best achieved before acquiring the glide slope when instrument meteorological conditions (IMC) prevail [3]. This result has implications for the design of CTR instrument approaches.…”