his own business building and marketing miniature gasolinepowered race cars, and within a few years Hiller Industries was producing 350 model cars per month and earning $100,000 per year. During this time, he and his father invented a diecasting machine based on a cooling process that increased the strength of the aluminum castings used in his Comet race car. The invention proved to be so significant that, in 1940, the War Department contracted with Hiller Industries to produce aluminum parts for military aircraft. During World War II, the company had two shifts of employees, seven casting machines, and a payroll of $300,000 per year. Anticipating a postwar decline in the demand for aircraft parts, he conceived ways of using the casting machines to produce aluminum kitchen utensils and briefly manufactured toy water pistols known as the Hiller Atom Ray Gun.
Mr. Hiller’s fascination with the challenges and possibilities of helicopters was stimulated by descriptions of Igor Sikorsky’s experiments with rotary-wing aircraft. Hiller reasoned that a coaxial rotor design without a tail rotor would overcome some of the complexities and instabilities of Sikorsky’s single-rotor configurations. He first built a model, followed by a full-sized helicopter named the XH-44 “Hiller-Copter.” This aircraft was constructed mostly of components scrounged or manufactured by his team of engineers and craftsmen and was powered by a civilian aircraft engine supplied by the War Production Board. Hiller conducted the test flight of the XH-44 himself, teaching himself to pilot it in the process, in Memorial Stadium at the University of California at Berkeley in the summer of 1944. On August 30 of that year, he held a public demonstration in San Francisco—the first successful flight of a helicopter in the western United States.
After a brief association with renowned industrialist Henry J. Kaiser, Mr. Hiller and investors formed United Helicopters Inc. in 1945, later renamed Hiller Aircraft Company. The company’s goal was to capitalize on the postwar market for low-cost helicopters for the general public by offering an improved version of the XH-44. However, this market failed to materialize, and, after a near-fatal crash, Mr. Hiller developed an alternative single-rotor configuration using stabilizing paddles, called the