Blind Flying Accomplished

Totally blind flying, solely by the aid of navigating instruments, became an accomplished fact for the first time last week. Lieutenant James Harold ("Jimmy") Doolittle, 33, "best Army Flyer," did it, at Mitchel Field, L. I. Thereby he completed eleven months' experiments for which the Daniel Guggenheim Fund for the Promotion of Aeronautics borrowed him from the Army Air Corps, and which presaged the highest safety in flying through no matter what weather.

Blind flying, where nothing of the ground or horizon can be seen, is the terror of aviation. At the speed of plane flight (100 m.p.h., usually) a pilot loses his sense of balance. At night or in fog, where he cannot orient himself against ground objects, he flies to one side, his wings tilt, the plane goes up, down or, happily, level. He does not know. His instruments go "hay wire." He is helpless. In terror he may try to guide himself. Generally that is useless. Experienced professional pilots, particularly on the night mail routes, often set their planes at neutral, take their hands off the controls, fold their arms and apathetically wait to get out of the fog, or to crash.

Three new instruments developed/- during the eleven months' work made Lieutenant Doolittle's work possible. Those instruments: 1) Visual radio direction finder consisted of two reeds vibrating in consonance with a new short range radio beacon at Mitchel Field. When the plane is directly in the path of the beacon, the reeds vibrate uniformly. When the plane is off course, one reed fibrillates faster than the other. The closer the plane is to the beacon, the more intense the vibration. 2) Artificial horizon showed instantly at what angle the plane was flying in relation to the ground, whether and how the wings were tilted, whether the nose was up, down or level, and to what degree. 3) Barometric altimeter showed to within a very few feet how far above the ground of a particular field, in this case Mitchel Field, the plane was at all times. Because the action of this altimeter depends upon barometric pressure, a variable factor, a ground crew was obliged to radiophone Lieut. Doolittle air pressure conditions. In development are more independent instruments, the sonic altimeter by Dr. Elmer Sperry and the radio altimeter by General Electric Co. They will sensitively record the time and therefore the distance which a sound or radio impulse travels from a plane to the ground and back.

A two-seater, dual control Consolidated biplane was equipped with these new instruments, plus of course the usual flying equipment, and put on the field. Harry Frank Guggenheim, 39, president of the Guggenheim Fund and Ambassador-nominate to Cuba was present. He and Lieutenant Doolittle had an argument. The Lieutenant wanted to fly the plane alone. Mr. Guggenheim, a flyer himself, insisted that Lieutenant Benjamin Kelsey, who had assisted in the research, occupy the front seat, to take control in case accident happened. Piqued, daring (TIME, Sept. 30) Lieutenant Doolittle consented. He crawled into the rear cockpit, hauled an opaque cloth entirely over himself and instruments, which were illuminated, gave the plane the gun. Off were the two men. Lieutenant Kelsey with his arms resting on the gunwales, Lieutenant Doolittle completely shrouded. Fourteen miles in all he flew, seeing nothing but his instruments. Certainly, assuredly, he made an excellent three-point landing within a few feet of his takeoff.

Enthusiastic were the comments of aviation experts on the successful experimental flight. David Sinton Ingalls, Assistant Secretary of The Navy for Aeronautics: "Consider this achievement of inestimable value to aviation." Edward Pearson Warner, Editor of Aviation, Mr. Ingalls' predecessor in the Navy Department : ''An epic of aviation. Nothing approaching its importance has been accomplished within the past two years." Thurman Harrison Bane, chief of The Aviation Corp.'s technical staff: "Doolittle's flight marks the first stage in man's conquest of flying in fog, now aviation's greatest obstacle." Charles Sherman ("Casey") Jones, president of Curtiss Flying Service: "The mechanical perfection of the new instruments employed required thorough testing by an expert pilot before they could be judged." Harry Frank Guggenheim: "The results of the experiment will be made available to any manufacturers of planes or air transport operators who wish to consider equipping their products for this kind of flying."

/-Through cooeperation of the Guggenheim Fund, U. S. Bureau of Standards, U. S. Army and Navy, Pioneer Instrument Co., Taylor Instrument Co., Sperry Gyroscope Co., Bell Laboratories, Radio Frequency Laboratories, Kollsman Instrument Co., and Professor William Brown of Massachusetts Institute of Technology.