Abstract: Signals from a source of flight path data, normally a memory device which stores forward-looking radar data, for example, are sampled in "reverse-time". That is, the data points along the flight path are taken in reverse order relative to the direction of flight. By simple circuits, the signals from the flight path data source are modified to conform with the basic criteria of the desired flight and with other desired parameters such as vertical acceleration and velocity limits so that a reverse-time flight simulation is made. The special "inside-out" form of indicia is a pair of bands which are fence-like in appearance and form the vertical sides of a tunnel-like outline, along the vertical center of which is the desired flight path. By generating these bands on a cathode ray oscilloscope with vertical displacements in accordance with the desired flight path and relative vertical widths in perspective with the range, the curved center line is easily followed.