Choppers are now associated mostly with militaries, hospitals, news reporting and other institutional uses. But they were once seriously touted as mass transit vehicles, the original flying car. It all came to an end in 1977, when helicopter commuting came to a sharp end when four passengers were killed in the Panam rooftop disaster. Efforts to revive commercial passenger helicopter service has been periodically revived since, but everyone's failed at it -- including future president Donald Trump.