This is well before TSA but plane hijacking used to be common occurrence: "Between 1968 and 1972, more than 130 American airplanes were hijacked. Sometimes there was more than one hijacking on the same day. "

https://www.vox.com/2016/3/29/11326472/hijacking-airplanes-e... https://en.wikipedia.org/wiki/List_of_aircraft_hijackings#19...