Embodiments of the invention provide a method and apparatus for indicating aircraft height relative to an obstruction in a
terrain awareness
warning system. The method includes receiving data indicative of geographic features of an obstruction, lateral distance of the
geographic feature from an aircraft, height and flight path of the aircraft, calculating a projected height of the aircraft at the location of the obstruction using the data, generating a result
signal, and displaying a
colored indication on a display screen based on the result
signal. The apparatus includes inputs for signals from instruments measuring height, flight path, and location of an aircraft, as well as an input for an instrument providing information about geographic features of
terrain surrounding the aircraft. The apparatus includes a means for employing the signals to calculate an
effective height of the aircraft relative to the
terrain, and a screen display for graphically displaying the results of the calculation.