Sikorsky S.55, 1956

Geoffrey Martin.  The Town.  A Visual History of Modern Britain.  Vista Books, 1961.

According to its Wikipedia entry, "The Sikorsky H-19 Chickasaw, (sold commercially under its Sikorsky model number, S-55) was a multi-purpose helicopter used by the United States Army and United States Air Force. It was also license-built by Westland Aircraft as the Westland Whirlwind in the United Kingdom."

After being withdrawn from military service in 1969,  a novel campervan-like "Heli-Camper" conversion—featuring a built-in mini-kitchen and sleeping accommodations for 4—was also offered by aftermarket modification companies.  Winnebago got into the act, modifying S.55's as "The Flying Winnebago."