57-1620 was a Sikorsky H-19D-5-SI Chickasaw
History
Built as c/n 55-1180, 57-1620 was passed to the United Nations, as ONU-71620, during July 1960, for use in Congo. Captured by Katangese forces in 1961 and briefly used by them, the helicopter was still around when Katangan secession ended in 1963, but was never recaptured by UN.[1]
