Evaluation of cross-pointer-type instrument display in landing approaches with a helicopter

SUMMARY - .... An evaluation of a landing-approach instrument display incorporating a cross- pointer presentation has been conducted in landing-approach tests with a helicopter. The display consisted of a vertical- situation-flight-director indicator, a horizontal-situation indicator, and small vertical-scale instruments for the presentation of airspeed, ground speed, vertical speed, range, and height. The tests of the display were conducted under simulated IFR (Instrument Flight Rules) conditions along a 6O glide slope at approach speeds of 30 and 60 knots. The results of tests of four configurations of the attitude-guidance elements d the display showed that course guidance information in the form of control-command (flight- director) signals provided more precise control of course than that provided by course- deviation and ground-track angle information. With the best of the four configurations of slope guidance information, satisfactory guidance along a 6'