The present approach guidance scheme is one of controlling the aircraft's velocity vector; however, this scheme has two major disadvantages: it's a difficult flying task for the pilot, and when the aircraft arrives tangent to the circular path, a violent maneuver is usually required to achieve the proper bank angle to stay on the desired circular path. An improved method for controlling the side firing AC-130 and AC-119 into circular attack geometry eliminates these disadvantages. Furthermore, with this improved system the bank angle rates never exceed 3 or 4 degrees per second. This control scheme was simulated on the analog computer and the results are presented graphically. The simulation showed that the bank angle, command-control scheme is effective for distances out to five circular orbit radii from the target and is effective for all aircraft headings (with one exception which is discussed in a stability study in the appendix). The initial test flight showed that the bank angle control scheme behaved very well, and its overall performance was near that predicted. Relatively minor modifications can incorporate this control scheme into existing analog computers on board the aircraft.

Also available as AD722412.