The US Army has recently listed a historic Sikorsky R-5 on the GSA Auctions website.

GSA (in full, General Services Administration) is an independent agency of the United States government established in 1949 to help manage and support the basic functioning of federal agencies.

The specific helicopter carries a 1951 fiscal year serial of 51-24352, and is not complete as the image below from the auction specification online shows.

The aircraft has been in the care of the US Army Aviation Museum at Fort Rucker in Alabama for some years, but is now surplus to their requirements and thus being disposed of.