Although throttle-dependent linear acceleration would generate flight load in the direction of the flight path, pilot-induced control maneuvers could generate the extreme flight loads that may be aggravated by inadvertent atmospheric conditions. Aircraft weight is primarily determined by the air load generated by maneuvers in the pitch plane. Therefore, the associated V-n diagram described in Section 5.7 is useful information for proposing candidate aircraft configurations. Section 3.6 describes the six deg of freedom for aircraft motions – three linear and three angular. Given herein are the three Cartesian coordinate planes of interest.
5.3.1 Pitch Plane (X-Z) Maneuver (Elevator/Canard-Induced)
The pitch plane is the symmetrical vertical plane (i. e., X-Z plane) in which the elevator/canard-induced motion occurs with angular velocity, q, about the У-axis, in addition to linear velocities in the X-Z plane. Changes in the pitch angle due to angular velocity q results in changes in CL. The most severe aerodynamic loading occurs in this plane.