Back in the mid-1980s, so much was made of the Soviet Mi-24 Hind's armor protection. The Hind was often described in popular media (commercially available books and mags) as a "Flying tank". (Stingers in Afghanistan: "Hold my beer.") Apparently, based on combat experience in Vietnam, the US briefly toyed with designs for both an armored scout helicopter and an "armored arial personnel carrier". It doesn't look like either got past the blueprint phase.
Blue Thunder vaguely resembles the armored scout (so that I wonder if the producers had seen Sikorsky's mock-ups).
https://www.twz.com/air/these-heavil...g-the-cold-war
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