This was likely a conversion of Sikorski S-55 helicopters that were retired from the US military around 1969/1970. The look of this helicopter reminds me of t

This was likely a conversion of Sikorski S-55 helicopters that were retired from the US military around 1969/1970. The look of this helicopter reminds me of the outwardly similar Sikorski S-58 that was used in the TV series "Riptide". I saw a few episodes of that as a child and I guess I'll never be able to forget that particular association.