Automatic flare transition penetrating wind shears

Abstract

In this paper, the development of a digital three-dimensional automatic control law designated to achieve an optimal transition of a large commercial aircraft between the glideslope conditions and the desired final touchdown condition is presented. The linearized equations representing the perturbed motion of the aircraft from the nominal glideslope trajectory are presented. A method of incorporating the spatial, low-level wind shears into these perturbed equations of motion is indicated. It is shown that the system equations then assume the familiar form of the linear regulator problem, acted upon by a constant disturbance. A design procedure is presented to compute a digital, time-invariant, optimal control law for the discrete regulator problem acted upon by a constant disturbance. The response trajectories presented demonstrate the capability of this controller to perform optimal flare maneuvers in the presence of various wind shear conditions.