Showing a considerable advancement from its earlier designs, Sikorsky's H-5 helicopter gained its greatest fame during the Korean War when it was called upon repeatedly to rescue pilots shot down behind enemy lines and to evacuate wounded personnel from frontline areas. More than 300 were built, with this one being ferried form Elgin AFB, FL to Patterson Field for the USAFM in March 1955

The R-5 was originally built by Sikorsky as its model S-48. It was designed to provide a helicopter having greater useful load, endurance, speed, and service ceiling than the Sikorsky R-4. The R-5 differed from the R-4 by having an increased rotor diameter and a new, longer fuselage for two persons in tandem, though it retained the R-4's tailwheel-type landing gear. Former USAAF 43-46607. Operated by the RTAF 1953-1970. The plane was designated Helicopter No. 1A (H.1A ฮ.๑ก).

I find it really fascinating to see these old helicopters/aeroplanes and to understand how the types in service today have evolved from them. The boom in helicopter development is particularly interesting as the rapid advances post-WWII quickly opened up possibilities that couldn't be contemplated previously. The improved capabilities of the H-5 became extremely useful during the Korean War for the timely rescue of downed pilots and for Medevac missions.