Bell OH-58 Kiowa Military Helicopter

Development
On 14 October 1960, the United States Navy asked 25 helicopter manufacturers on behalf of the Army for proposals for a Light Observation Helicopter (LOH). Bell Helicopter entered the competition along with 12 other manufacturers, including Hiller Aircraft and Hughes Tool Co., Aircraft Division. Bell submitted the D-250 design, which would be designated as the YHO-4. On 19 May 1961, Bell and Hiller were announced as winners of the design competition.
• Light Observation Helicopter (LOH)
Bell developed the D-250 design into the Model 206 aircraft, redesignated as YOH-4A in 1962, and produced five prototype aircraft for the Army's test and evaluation phase. The first prototype flew on 8 December 1962. The YOH-4A also became known as the Ugly Duckling in comparison to the other contending aircraft. Following a flyoff of the Bell, Hughes and Fairchild-Hiller prototypes, the Hughes OH-6 Cayuse was selected in May 1965.