The
Light Observation Helicopter (
LOH) program was a
United States Army program to evaluate, develop and field a light scout helicopter to replace the Army's aging
OH-13 Sioux. The program gained impetus with the advent of the
Vietnam War and was aided by advances in helicopter technology, specifically the development of the
turboshaft engine. Three of the aircraft evaluated for the program would eventually enter military service, one as a training helicopter and two as observation helicopters used for battlefield
reconnaissance missions.