The Effect of Windscreen Bows and Hud Pitch Ladder on Pilot Performance during Simulated Flight

Abstract

During the upgrade of the F-14 to the F-14D, pilots have expressed their concerns regarding the obscuration of the forward field-of-view due to the new Head-up Display (HUD) supports in conjunction with preexisting windscreen bows. An additional issue involves the proposed use of the HUD as the primary flight reference instrument. The HUD pitch ladder has been criticized for not providing enough information to enhance recovery from unusual attitudes. The purpose of the present study was twofold: (1) to measure the levels of “target” detection with and without windscreen bows, and (2) to measure unusual attitude recovery performance using two different HUD pitch ladder formats. During simulated flight, 12 subjects were required to make visual detections of enemy aircraft with and without the bows. Subjects were also required to recover from various pitch/roll combinations. Removal of the bows improved target detection. Results of the obscuration study showed that in the first 5 seconds into the flight 80% of the targets were detected with bows off, while only 60% were detected with bows on. Evaluation of the two HUD pitch ladder formats revealed that, at severe negative pitch attitudes, there was a marked performance benefit with the Enhanced HUD vice the Standard HUD. Possible improvements in current HUD pitch ladder formats were suggested which would convey more cues to accurately and rapidly determine aircraft attitude.