A Flight Investigation Of Control, Display, And Guidance Requirements For Decelerating Descending VTOL Instrument Transitions Using The X-22A Variable Stability Aircraft

The third flight research program using the variable stability X-22A aircraft was undertaken to investigate control, display, and guidance requirements for VTOL instrument transitions. The primary purpose of the experiment was to provide meaningful data related to the interaction of aircraft control system and pilot display characteristics on pilot rating and performance during a steep decelerating descending transition from a representative forward velocity (100 kt) to the hover under simulated instrument conditions. Thirty-seven evaluations were performed of combinations of five generic display presentations, ranging from position-information-only to four-axis control directors, and five levels of control augmentation systems, ranging from rate-augmentation-only to decoupled velocity responses and automatic configuration changes. Primary results of the program include the demonstration of an inverse relationship between control complexity and display sophistication, as was hypothesized in the experiment design, and the definition of acceptable and satisfactory control-display combinations.