AVIATION: An Eye for Helicopters

For helicopter pilots, all-weather blind flying without ground guidance at the landing site has been a long-sought goal. Last week in Dallas, the goal was reached by Bell Aviation helicopter division and Bendix Aviation, which successfully tested an "electronic road map" that tells a pilot exactly where he is within a 100-sq.-mi. area. Using the landing system, the helicopter took off and flew to within 20 ft. of its destination without the pilot's being able to see out.

Picking up steady impulses sent out by a master and two slave radio transmitters on the ground, a 40-lb. receiving unit in the cockpit computed the helicopter's position by triangulation. On a stationary navigational chart of the area, the pilot watched a moving pen track his course. For commercial pilots in crowded urban areas, the system promised to permit helicopter service no matter what the weather.