The Hughes TH-55 Osage was a piston-powered light training helicopter produced for the United States Army. It was also produced as the Model 269 family of light utility helicopters, some of which were marketed as the Model 300. The Model 300C was produced and further developed by Schweizer after 1983.
In 1958, prior to full-time production, Hughes provided five pre-production Model 269 examples to the U.S. Army for evaluation as a light observation helicopter to replace the aging OH-13 Sioux and OH-23 Raven. Designated as the YHO-2HU the helicopter was eventually turned down. 9 April 1959, the 269 received certification from the FAA and Hughes continued to concentrate on civil production. With some design changes, deliveries of the Model 269A version began in 1961. By mid-1963 about 20 aircraft were being produced a month and by the spring of 1964, 314 had been built.
While the Army hadn't found the Model 269 adequate for combat missions, in 1964 it adopted the Model 269A as its training helicopter to replace the TH-23 and designated it the TH-55A Osage. 792 TH-55 helicopters would be delivered by 1969, and it would remain in service as the Army's primary helicopter trainer until it was replaced in 1988 by the UH-1 Huey. At the time of its replacement, over 60,000 Army pilots had trained on TH-55 making it the Army's longest serving training helicopter. In addition to the US Army, Hughes delivered TH-55/269/300s to other military customers.
In 1964, Hughes introduced the slightly-larger three-seat Model 269B which it marketed as the Hughes 300. That same year, the Hughes 269 set an endurance record of 101 hours. To set the record, two pilots took turns piloting the aircraft and hovered in ground-effect for fueling. To ensure no cheating, eggs were affixed to the bottom of the skid gear to register any record-ending landing.