In 1961, twelve companies submitted proposals to meet U.S.Army requirements for a four-seat
turbine-powered light observation helicopter. After evaluation, three designs were selected and
5 of each: the Bell OH-4A; the Hiller OH-5 and the Hughes OH-6, were ordered for trials by the U.S.Army Aviation Board.
The prototype of this Model 206 made its first flight on 8 December 1962.
However the Bell OH-4A didn't win the competition, the helicopter was a success as the Bell 206 Jet
Ranger. Next to the commercial success the Jet Ranger entered after all also the military scene: the
Bell 206 Jet Ranger was ordered in 1962 by the US Navy as the TH-57 Sea Ranger. Due to the higher unit
price and significant deliver delays on the original winner of the 1961 U.S.Army competition for a light
observation helicopter, the Hughes OH-6, the U.S. Army reopened in 1968 the light observation helicopter
(LOH) bidding. This time Bell was the winner and an initial order for 2200 OH-58A Kiowa, a military version
of the Model 206A followed. Deliveries of the OH-58A helicopters began in May 1969. The Model 206 was
continues improved and it was the winner of the competition for the New Training Helicopter (NTH) on 30 March
1993. The U.S.Army ordered 157 as TH-67 Creek, followed by the U.S.Navy which ordered 320 as the TH-57.
Over 7700 Model 206 derivatives have been built.