Evening Star Newspaper, December 15, 1929, Page 115

THE SUNDAY —_— STAR, WASHINGTON, D. C., DECEMBER VIS, 1929. 350 MILES IN PILOTLESS PLANE “Mechanical Mike” Achicves Unparalleled Feat of Guiding p Airplane Frrom BY R. O. TODD. F all the robots lately invented to astonish the world of sci- ence, easily the most sensa- tional is the mechanical pilot which recently flew from Day- ion, Ohio, to Washington in a demon- stration fiight. Except for a distance of 30 miles not a human hand had to touch the controls; a fact that meant that the plane flew pilotless for about 350 miles, a record never approached by any other mechanical device. Riding in the plane, a tri-motored Army transport, were three men whose contributions to the advancement of aircraft science have made them ta- mous: Maj. A. H. Gilkeson, chief of the equipment branch at the Army Air Corps experimental laboratories at Wright Field, Dayton; Lieut. Albert F. Hegenberger, who piloted an Army plane to Hawaii on the first transpacific flight, and Elmer A. Speirry, jr., a co- developzr, with his father, of “Me- chaniea! Mike.” Mr. Sperry, sr., is the same interna- tionally known scientist who startled America a few years ago with his device that automatically keeps vessels on their true courses at sea. It consists of a gyro-compass, now used as stand- ard ecuipment by the navies of the United States, Great Britain, Japan, France. Italy and Russia. “yuring the epochal trip from Wright Field all went well with the three flyers untii they reached Leesburg, Va., omv 30 miles from Washington. There the propeller of a small generator which supplies current to the automatic ap- paratus went “haywire,” due to the weight which served as a governor to maintain a constant propeller speed. So the plane was brought into Bolling Ficl?, Washington, by Lieut. Hegenberger. During that portion of its flight which was conirolled by the automatic pilot the plane crossed the dangerous Allegheny Mountains. This, in the face of a terrific wind, is something of a feat even for a trained aviator, constantly alert at the controls. 3 FFHE automatic controls of the “stabilizer,” as Mr. Sperry calls his new invention, are con- tained in a housing measuring 14 inches squarc, located beneath the pilot’s seat. The entire de- vice weighs 50 pounds. It includes two gyro- cpes, one mounted vertically and the other horizontally, which actuate make-and-break elec'rical circuits operating the airplane controls —the rudder for direction, the elevator for up and down movements and the ailerons for maintaining the plane on an even keel under all conditions of wind and weather. The actiocn of the gyroscope is familiar to all children who roll hoops or spin tops. So long as the top or hoop is motionless, it tends to fall, but when it is rotating, it will remain up- right. The same holds true in the case of the airplane, Mr. Sperry, sr., found after numerous tests. The main trouble in operating aircraft lies in the danger of overbalancing the appa- ratus when a sudden gust of wind strikes from an unexpected direction, taking the flyer com- pletely off his guard. The gyroscope stabilizer, as hinted above, corrects all such upsetting movements. Beoides the trip to Washington, recent experi- mental flights with the robot have been con- ducted between New Bedford, Mass., and New York City; New York and Wright Field, and Wright Field and Detroit, all under the direc- tion of Maj. Gilkeson, Mr. Sperry, jr.; Hegen- berger and Capt. Cyrus A. Blair, technical ex- pert of the Air Corps and one of the developers of the device. The flight between Dayton and Detroit was hl satisfactory in every respect, Lieut Hegenborger says. The robot functioned with- out a hitch, requiring only two adjustments in course direction, made necessary by changing wind conditions. The “mechan- that did the trick is shown ical mike” at right. The crew of the pilotless planc: Maj. A. H. Gilkeson, left :Elmer A. Sperry, jr., and The development of automatic control of air- planes received great impetus, Mr. Sperry jr., points out, by the growing use of large transport planes in commercial and military service. The first Sperry model, known as the “Sperry gyro- scopic stabilizer,” was built and installed in 8 Curtiss flying boat some years ago by the late Lawrence Sperry, brother of Mr. Sperry, jr. Its further development as an instrument for aero- nautical navigation was retarded by the slow de- velopment of the airplane and the lack of public interest in aviation prior to and just after the World War. However, the same principle has been in use for some years in Mr. Sperry, sr.’s, devices for automatic control of ships at sea. From the military standpoint, the greatest value in the perfection of the new device lies possibly in its application to large bombing ex- peditions. Experiments have shown conclusively that a small torpedo plane, equipped with thc automatic pilot, may be controlled in flight by radio. Using this device it may be possible for the army bomber of the future to be a small, fast, two-man plane, controlling by radio a large fleet of torpedo planes. Thus, at a minimum use of planes and personnel, greater results may be obtained than under present bombing procedure. In this connection it is interesting to note that another of Mr. Sperry, sr.'s., important de- velopments is a unique type of aerial torpedo. Tests made in Curtiss planes have shown com- nlete automatic control with a high degree of accuracy at a target 35 miles distant, with the promise that the torpedo can function at three times this distance. The torpedoes rose to a vredetermined height, then automatically leveled off for the flight, were automatically guided with a high degree of precision, and when any prede- termined number of miles had been traversed. suddenly turned and flew downward. Each car- ried an enormous charge of TNT with sensitive contact fuses, enough, in fact, to blow up a fortress or an ammunition house. A power catapult and aiming device that ould be assembled quickly and put on board & truck was also devised by the Sperrys. Th: catapult delivered these torpedo-planes into the air at flying speed, operating with practical per- Dayton, Ohio, to Wash- ington, D. C., With Human Hands { Touching Controls Only Once. fection. The source of energy, strangely enough, was a tiny 4-horsepower gasoline en- gine. It was possible to discharge an aerial torpedo every six minutes. ACCORDING to W. L. Saunders, president of the United Engineering Society, Mr. Sperry has been highly successful in devising two solu- tions for the problem of dropping bombs from airplanes. Mr. Saunders explains: “In the past anti-aircraft guns have frew- quently driven airplanes so high that it was found almost impossible to hit a target with the bombs. It had been humcrously said that ‘they were fortunate if they hit in the same county. But Mr. Sperry has developed an automatic bomb-dropper with a gtabilizer equipment for handling the bombs and dropping them with great exactness. “The stabilizer on this device always points to the center of the earth, which is a great ad- vantage to the pilot. A second way of dropping bombs from planes employs the use of complete wireless control of a bomb just as it is being dropped. Wireless direction is accomplished through an antenna attached to the bomb. When messages are received by the antenna a mechanism is set in motion which automatically adjusts another contrivance to direct the bomb’s flight. In one test a big mark was placed on the top of the umbrella, in the shape of an arrow, which could be seen from the airplane. This arrow was covered with aluminum paint, making it easily visible on the umbrella’s black back- ground. From the plane the descending bomb looked like a great 8-foot ball with a 14-inch mark on it, thereby enabling the operators quickly to identify and direct it by the methods mentioned.” . REAR ADMIRAL BRADLEY A. FISKE, U. S. N, retired, tells an absorbing story about how Mr. Sperry developed the predecessor of the new “Mechanical Mike,” the device which Lieut. Albert F. Hegenberger. automatically keeps vessels on a true course &t sea: “Mr. Sperry early accumulatcd a library om . the gyroscope, in which he Lad long been in- terested. He had become familiar with the actual magnitudes of the gyroscope reactions : apart from theory, and some years prior to the World War was asked to aid the Navy on a num=- - ber of problems. He had intimated to the Navy that he believed he could overcome the intoler- able troubles of the magnetic compass by means of larger and larger masses of steel in ships. The magnetic compass not only possessed cer= tain vagaries but it also had become treacherous, for it gave no indication of the magnitude of the error of its erratic readings. In submarines these troubles were intensified. It occurred to Mr. Sperry to abandon magnetism and inveat a compass that would be based on some other field of force equally available at all points on the earth's surface, but not disturbed by the conditions encountered inevitably on all iron ships. The naval technical division believed Mr. Sperry was right in selecting the gyrcscope and depending upon its reaction to the rotation of the earth, a fact which was just beginning vo be appreciated. “After trials on a New York merchant ship on the Norfolk run, his first gyro-compass was piaced in the powder magazine of a destroyer at the Brooklyn Navy Yard. Here it was sur- rounded by steel walls. No magnetic compass could have functioned, but the gyro placed thera worked and sea trials proved it to have extraor- dinary accuracy. They included a high-speed run which necessitated firing the forward boil- ers. These tests demonstrated that the gyroe compass dealt with absolute geographical mee ridians under all conditions, instead of with the erratically placed magnetic meridians, which converge at the Magnetic Pole, 1,800 miles from the actual pole, which must be used in navie gation. *Soon after these trials Mr. Sperry’s first gyros compass was installed on the Delaware in 1914. 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