BLIND LANDING GUIDE

Taranaki Daily News, 14 September 1940, Page 10

BLIND LANDING GUIDE

PILOT'S INVENTION

San Francisco, August , 8. For years Captain Allan ■ . A.; .'Barrie, veteran Western Air Express' pilot, iew his Los Angeles-Salt Lake City run in . weather that ranged from sun-bright to foggy. When he manoeuvred his big Douglas transport "on instrumentsf — navig^ting from the scores of dials that indicate altitude, speed, direction, rate-of-climb and other necessities— Captain Barrie followed set methods. He used a prepared blank chart on which -to figure his procedure for approaching ; an airport when visibility was poor and it involved plenty of mathematics. Operating like a simplified slide rule, his "approach guide has adjusxable indicators for airport altitude, the aei'oplane's height above the field, the compass course, and the number' of minutes the pilot must fly to complete his problem. Assuming the airport stands 1000 feet above sea level, the "approach guide" is set at that figure. The moment the , plane passes over the 'cone of silence"— the sudden cessationv.iof radio beam signals, which means' -the ;ship_ is directly cibove . the trsnsrnission station— the pilot begins descent according to the ■ Barrie plotting device. ■ ■ The topmost figure now registers 10,500 feet. This is the theoretical altitude at which the plane has neared the . field to escape high peaks. • Additional j "approach guide" figures name the com- | pass needle readings for the standardised | one-minute 180-degree turns. A plane, flying 120 miles an hour, dropping 500 feet a minute for three minutes at 360 ! degrees on the compass (which is north at 9000 feet) swings to ,180 degrees • south), then flies seven minutes and the pilot finds himself at 4500 feet. Another 180-degree turn; another four minutes of flying; and, presto! there is "the airport right -under the landing wheels. Captain Barrie said his device will be invaluable to "blind-flying students, army flyers and to aeroplane pilots.