This word surged in use during the 1970s when airplanes became a frequent target.
(The more specific skyjack never fully caught on.)
Who commandeered planes in the '70s? Among others, Cubans, Syrians, Soviets, South Vietnamese, Palestinians, and Americans. Motivations ranged from religion to politics to cash.
As the New York Times News Service reported,
"Sooner or later, an airline hijacking is going to result in a real disaster hundreds dead in a crash, or a bloody shootout in the sky, or even the reality of something as bizarre as last weekend's threat to crash a hijacked Southern Airline's plane into the Oak Ridge atomic installation." Tom Wicker, November 14, 1972