AID FOR AVIATION

Evening Post, Volume CXXVI, Issue 151, 23 December 1938, Page 3

AID FOR AVIATION

DIRECTION FINDER

AUTOMATIC OPERATION

With the aid of a new radio instru« ment, an automatic direction-finder, a transport aeroplane carrying sixteen . passengers found a hidden navy truck a dozen miles away as readily as a; hound on a hot scent finds its game, says the "New York Times." The de- • vice was demonstrated, after several months'of intensive secret flight tests, in an American Airlines Douglas, which took off from Floyd Bennett Field. It has been perfected by the Sperry Gyroscope, Company, of Brooklyn, working with the R. C. A. Manufacturing Company. A dial placed on a mounting in the centre.Jof the pilot's - cockpit shows by the direction of a needle, actuated by the radio device, the precise direction from which radio signals to which it is tuned are emanating. In the demonstration a truck from the Naval Reserve Base at the Municipal Airport, on which a twenty-watt transmitting set had been mounted, was sent out on the Long Island roads and told to hide. An hour later a Douglas DC-3, flown by Captain William Dunn, of the airline, left the field. To the pilots in the cockpit and the , newspaper and technical writers aboard, who were allowed to come up forward in pairs to see what was happening, the needle on the directionfinder immediately and continuously showed the direction which the plane should take. BEHIND A HANGAR. Its message was followed and then in a very few minutes the truck, from, which signals were coming, was found , hidden-behind a hangar at the Valley Stream Airport. The device indicated also when the plane was immediately over the source of the signal. ; In a further test with a new load of passengers the device picked up the WEAF broadcasting station at Bellmore, Long Island, and guided the pilots to a point immediately over its towers." ■ Engineers of the Sperry Company, explained that,since November, 1937, the Government had required that all transport planes be equipped with a shielded loop antenna and directionfinder to help locate the aeroplane and make more positive radio reception of the airway beams under adverse weather conditions. Such loops, they added, gave excellent information to the pilot but required close concentration and attention. The new device, they said, performed these functions automatically and continuously without diverting the pilot from any other activity. , > The automatic direction finder only requires the pilot to tune to a station. Then the pointer on the instrument indicates the exact bearing of the station and continues to give the bearing to the point of passing over the source of the signal. MOUNTED HORIZONTALLY. The face of the instrument is mount ed horizontally, so that the azimuth readings are shown in the plane in which they are measured. The pilot , thus can orient himself by visualising the location, of the station with respect * to the craft he is flying as being in the direction of the arrowhead, relative to the miniature aeroplane shown 8n the face of the instrument. Navigation scales, also shown, eliminate the need of all arithmetic. All dials and switches are plac-d within easy reach on the instrument. J. G. Flynn, jun., superintendent of communications of the airline and chairman of the sub-committee for radio direction finding of the Radio Technical Committee for Aeronautics, has conducted the test flights with the new finder. He said that it simplified the work of pilots and enabled them to operate with the least effort.

"It is a most valuable supplement to air safety and one of the jmost important aids developed in the last ten years," he added. "It takes the guesswork; out of navigation. A number of recent accidents have been caused by the pilot being lost. The finder should eliminate such causes."

Francis Moseley, an engineer of the* Sperry Company, who has been active in the development of the device with R.C.A. engineers, said it could be used with either an exterior or an interior loop on the plane. He added that experiments were being conducted to link; the automatic direction finder with th©