Helicopters

The airlift experience in World War II also included the AAF’s first operational deployment of helicopters. Brilliant Russian émigré Igor Sikorsky had studied rotary-wing aircraft in Imperial Russia before settling in the United States after the Russian Revolution of 1917–18. Following major success with large flying boats, Sikorsky returned to helicopter development in the 1930s. The historic flight of the Sikorsky VS–300 in 1939 is generally acknowledged to be the first use of modern, practical helicopter design. Military interest led to a production model, the Vought-Sikorsky R–4, introduced in 1942. Its 180-hp engine gave it a top speed of 75 mph and a range of 130 miles. The R–4 could lift only one passenger in addition to the pilot. The aircraft initially served as a coastal-patrol helicopter in the United States, entering service in 1943. The same year, several helicopters were sent to Burma to see how the unusual-looking vehicle would operate in hot, humid jungle environments. The AAF eventually received 132 models of this pioneer helicopter design.