SIKORSKY ARCHIVES PHOTO


THE SHIP THAT LAUNCHED A THOUSAND FLIGHTS: SIKORSKY’S VS-300 continued


to the Vertical Flight Society, “and in exploring methods of controlling a helicopter in flight and in its forward propulsion.” In the 20th century’s first decades, aviation focused on


expanding the Wrights’ successes. Wilbur Wright’s 200-plus demonstrations, starting in 1908, in France, Italy, and Germany whet the appetite of thousands of inventors, some of whom


a common rotorcraft design feature. La Cierva’s success caught the attention of Harold Pitcairn,


a Pennsylvania business owner who had founded the pre- decessor to Eastern Airlines and an airplane manufacturing company, both bearing his name. He licensed rights to develop autogiros. On Dec. 18, 1928, a Cierva C.8W assembled by Pitcairn Autogiro Company became the first rotary-wing aircraft to fly in the United States. According to the Vertical Flight Society: “Pitcairn subsequently developed a range of autogiros and related technol- ogies” and patents. Many found their way into the first American helicopters. Among them was Pitcairn’s articulated rotor-head technology, which Sikorsky licensed for the VS-300.


Born of Necessity Te VS-300 was a last-ditch effort to save Sikorsky’s company. Parent United Aircraft Corporation owned engine maker Pratt & Whitney, Vought Aircraft, and Hamilton Standard Sikorsky. Te company merged the latter two into the


Igor Sikorsky prepared this


drawing as part of a 1930 US patent application for a


“direct-lift aircraft” with a single


overhead lifting rotor and a single tail


antitorque rotor, a configuration very


similar to the one he and his team would


build and fly 9 years later.


pursued vertical flight. One was Danish engineer Jacob Ellehammer, whose 1912–16 flights in his aircraft with two 25-ft.-diameter (7.62-m-diameter) counter-rotating discs— powered by a custom-built 36-hp. (27-kW) radial engine— demonstrated an early form of cyclic control.


The Autogiro’s First Flight World War I focused aviation’s attention entirely on fixed- wing craft. After the war, numerous inventors returned to vertical lift. Among the most influential was a man who never built a helicopter: Juan de La Cierva, inventor of the autogiro. Te Spanish engineer’s aircraft used a tractor engine to propel a fixed-wing airplane and an unpowered rotor to help lift it, with the rotor spinning in autorotation in forward flight. La Cierva’s aircraft gained acceptance and success in the 1920s in Spain and England, where he established the Cierva Autogiro Company. La Cierva concentrated on refining rotor design, relying


on other manufacturers to provide the fixed-wing portion of the autogiro. Tis led in 1922 to his most important rotorcraft contribution: the flapping-hinge rotor, which offsets the differential lift of advancing and retreating blades. Flapping reduces roll resulting from dissimilar lift. It became


44 ROTOR DECEMBER 2022


Vought-Sikorsky Division. After emigrating to the United States in 1919, Sikorsky had made his name building flying boats for the US Navy and airlines, most famously Pan American Airways. But in 1938, the Navy declined to order the next-generation XPBS-1 “Flying Dreadnought.” All previous aircraft orders had been filled. With none on the horizon, United Aircraft planned to shutter Vought-Sikorsky. A company vice president summoned Sikorsky to the


Hartford, Connecticut, headquarters to break the news and suggest to Sikorsky that he could undertake a new, small research project. Sikorsky proposed developing the direct-lift aircraft for which he had submitted a patent and plan in 1930, provided he could retain a team of engineers and mechanics. He estimated the work would cost $60,000. United Aircraft gave him $30,000. Working nights and weekends, Sikorsky and his team


turned that 1930 idea into a test aircraft, the H-3. In a 1930 paper titled “Te Helicopter Problem,” Sikorsky explained to management about the H-3 design: “Te most important problem to be solved in order to achieve complete success and to build a directly useful machine appears to be in the question of proper stability and control.”


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