Vertical guidance.

Calculations for the vertical axis, rather than the longitudinal axis. The control law vertical axis input data are: Desired Altitude, Altitude Integral, Altitude Integral Gain, Altitude Integral Limit, Altitude Error Scale Factor, Magnitude limit for delta altitudes. The major output from Vertical Guidance is the altitude error for the selected vertical guidance mode. Vertical speed hold (VERT SPD). A basic guidance mode, providing vertical guidance to maintain an operator selected vertical speed;