It's a Northrop YC-125B Raider. PZ was the prefix for Surinam in S America. The 'B' in it's description meant it was built for the USAF for rescue work in the Arctic in the early 50s. It was under powered and not used for long by the military. The aircraft in the photo was used in the construction of new airfields and was taken about 1959 or 60.The YC-125 was a STOL aircraft, but this one kept on having landing accidents!