CH-136 Kiowa

OH-58 Kiowa
An OH-58D Kiowa Warrior taking off from Forward Operation Base MacKenzie, during the Iraq War in October 2004.
Role	Observation and reconnaissance helicopter
National origin	United States
Manufacturer	Bell Helicopter
First flight	Bell 206A: 10 January 1966 OH-58D: 6 October 1983 OH-58F: 26 April 2013
Introduction	May 1969
Retired	January 2017 (U.S. Army Combat Role)
Status	In service
Primary users	United States Army Republic of China Army Royal Saudi Land Forces Croatian Air Force Hellenic Army
Produced	1966–1989
Number built	2,200
Unit cost	OH-58D: US$4.9 million (1990) OH-58D KW: US$6.7 million (1990) KW retrofit: US$1.3 million (1990)
Developed from	Bell 206

The Bell OH-58 Kiowa is a family of single-engine, single-rotor, military helicopters used for observation, utility, and direct fire support. Bell Helicopter manufactured the OH-58 for the United States Army based on its Model 206A JetRanger helicopter. The OH-58 was in continuous U.S. Army service from 1969 to 2017, when it was retired and replaced in this role by the AH-64 Apache.

The latest model, the OH-58D Kiowa Warrior, is primarily operated in an armed reconnaissance role in support of ground troops. The OH-58 has been exported to Austria, Canada, Croatia, the Dominican Republic, Taiwan, and Saudi Arabia. It has also been produced under license in Australia.

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.

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.

When the YOH-4A was rejected by the Army, Bell went about solving the problem of marketing the aircraft. In addition to the image problem, the helicopter lacked cargo space and only provided cramped quarters for the planned three passengers in the back. The solution was a fuselage redesigned to be more sleek and aesthetic, adding 16 cubic feet (0.45 m³) of cargo space in the process. The redesigned aircraft was designated as the Model 206A, and Bell President Edwin J. Ducayet named it the JetRanger denoting an evolution from the popular Model 47J Ranger.