The Cessna L-19 / O-1 Bird Dog was a liaison and observation aircraft. The Bird Dog had a lengthy career in the U.S. military as well as in other countries.


The HU-1A (later redesignated UH-1A) first entered service with the 101st Airborne Division at Fort Campbell, Kentucky, the 82nd Airborne Division, and the 57th Medical Detachment. Although intended for evaluation only, the Army quickly pressed the new helicopter into operational service and Hueys with the 57th Medical Detachment arrived in Vietnam in March 1962.