Flight trials of the head-up display (H.U.D.) in Meteor 7/8 and Hunter 12 aircraft

Head-Up Display is an information display which permits an overall transfer of information from both the display itself and the visual environment (forward view). This report is mainly a desoription of a flight investigation in a 12 aircraft of the many factors involved in a Head-Up Display but earlier tests made in a Meteor 7/8 aircraft are also reported. The Hunter trials were conducted in three phases. Phase 1 trials were used to cheek picture quality, to calibrate the system and develop G.C.A. procedure. In Phase 2, manual trimming of the flight director was used for (ab initio) directed take-off, terrain following, flare and overshoot, whilst conventional coupling was used for ILS approach. This phase also covered attitude sealing, velocity vector alignment, supporting raw information (leading to an electronic flight instrument display), wind screen coating effects and night flying. Attitude scaling was again considered in Phase 3, where further changes of display form were made, and an extended-field double reflector was tested. Other topics included 113 failure, error recording, computer-driven directed take-off and the use of non-pilots as subjects. Display form evolved as a3-bar director, with ancillary speed error and digital height components. The properties established were of continuous transition, ease of learning and accurate use, allowing an aircraft to be flown with low work-load at large speed- to-height ratios. Comments are also made on the reliability of the equipment during the trials.