HAT was the world's first commercial helicopter operator. The S-51 appears to be NC92803 which was delivered to the company from Camden, New Jersey, in September 1946. Air mail trials were flown in New York City, Boston and Philadelphia the following winter. A mail van is waiting on the right but we don't know where this photo was taken - do you? HAT filed for bankruptcy in October 1947. NC92803 went to the US Coast Guard as an HO3S, 233. It is now preserved in the Evergreen museum, Oregon. Photo from: Nationaal Archief (Netherlands)
This photo was added on 7 April 2021, and has since been viewed 139 times.