Syfy says it will air a marathon of episodes of "The Greatest American Hero," which hasn't been seen on U.S. television since its original run ended in 1983.

ADVERTISEMENT

The 20-hour event is to start July 4.

The action-comedy series aired from 1981-83, and starred William Katt, Robert Culp and Connie Selleca.

Katt portrayed Ralph Hinkley, a young high school teacher in Los Angeles who encounters extra-terrestrials while on a field trip in the desert. The aliens give him a red flying suit with special powers, but unfortunately Ralph loses the instruction book.

Culp plays a neurotic FBI agent who persuades Ralph to use his new powers to fight crime, while Selleca plays Ralph's girlfriend, an attorney.