The Hiller H-23 Raven was a three-seat utility helicopter used by the US Army during the Korean War.
The Hiller UH-12 was the first commercial helicopter to make a trans-continental flight across the United States. It was adopted by the US Army with the designation H-23 and by the US Navy with the designation HTE-1. More than 2,000 of all versions were built.
A small number of US Army H-23 Ravens arrived in Korea in February 1951. They were used for the rest of the war for medical evacuation and for battlefield observation and surveillance.