Issues and research needs concerning the use of head-up displays in air transports

Head-up Displays (HUDs) are being installed in air transports in order to allow manual approaches, landings, and takeoffs in poor visibility. HUDs make it possible to overlay and augment the real-world image with conformal symbols such as a flight path marker (FPM) which indicates the direction the aircraft is heading within the out-the-window (OTW) view. While HUDs have been operational on civil transports for over 10 years, design issues remain to be resolved with further research. Relatively extensive research has highlighted HUDs´ special sensitivity to clutter, but further research is needed to give designers the tools needed to compare HUD designs in a specific flight deck application. Research on unusual attitude recognition and recovery with HUDs has yielded solutions that when combined are only minimally adequate. Limitations in HUD coding abilities call out for a standard for indicating alerts, while limitations in HUD optics require more knowledge on pilot head activity