Bell YOH-4

The Bell YOH-4 (originally YHO-4) is a single-engine, single-rotor light helicopter, developed for the United States Army's Light Observation Helicopter program. While the YOH-4A was unsuccessful in the original LOH competition, Bell redesigned it as the sleek Bell 206A JetRanger for the commercial market, and enjoyed instant and lasting success. In 1967, the Army reopened the LOH competition, and the 206A-based OH-58 Kiowa was selected.