ModelC/N Derivatives & Versions ModelYearHistory HUP-1 / UH-25A Retriever HUP-2 / UH-25B Retriever HUP-3 / UH-25C Retriever H-25A / CH-25A Army Mule 1952 List of Operators of Piasecki PV-18 From Organisation with model PV-18 1948 US Navy 1948/65 1949 US Marine Corps 1949/64 1953 Aéronautique Navale HUP-2 / UH-25B Retriever 19 1953/65 US Army Aviation H-25A / CH-25A Army Mule 70 1953/58 1954 Royal Canadian Navy (1945-1968) H-25A / CH-25A Army Mule 3 1954/64 1978 Aviodome 1 1978/ Construction Numbers on database of PV-18 or its versions 70ch-25a32uh-25a234uh-25b1pv-18