Unified Theory for Aircraft Handling Qualities and Adverse Aircraft-Pilot Coupling

TLDR

The paper introduces a unified theory for aircraft handling qualities and adverse aircraft‑pilot coupling, including pilot‑induced oscillations. The theory is based on a structural human‑pilot model and a methodology that predicts handling‑quality levels, pilot‑induced‑oscillation ratings, and the frequency band of likely PIOs, incorporating cockpit force‑feel dynamics while excluding control‑sensitivity effects and being limited to single‑axis, linear vehicle models, with a discussion of extensions to nonlinear dynamics. The theory, derived from the feedback topology of the structural model, was validated against flight‑test data for 32 aircraft configurations simulated by the U.S.

Abstract

A unified theory for aircraft handling qualities and adverse aircraft-pilot coupling or pilot-induced oscillations is introduced. The theory is based on a structural model of the human pilot. A methodology is presented for the prediction of (1) handling qualities levels; (2) pilot-induced oscillation rating levels; and (3) a frequency range in which pilot-induced oscillations are likely to occur. Although the dynamics of the force-feel system of the cockpit inceptor is included, the methodology will not account for effects attributable to control sensitivity and is limited to single-axis tasks and, at present, to linear vehicle models. The theory is derived from the feedback topology of the structural model and an examination of flight test results for 32 aircraft configurations simulated by the U.S. Air Force/CALSPAN NT-33A and Total In-Flight Simulator variable stability aircraft. An extension to nonlinear vehicle dynamics such as that encountered with actuator saturation is discussed.