Today we're used to the fact that you can't board a plane without taking off your shoes and belt, getting your ID checked, your body scanned and clearing your carry-on of pocketknives and bottled water.
But 40 years ago—a time before the way to your terminal was littered with x-ray machines, body-scanners, metal detectors and a small army of security guards—you could just buy a ticket and walk onto a plane.
There were a few drawbacks to the ease of travel. But it was also the golden age of hijacking. From 1961 to 1972, more than 150 commercial flights were hijacked in the U.S.
As the search for Malaysia Airlines Flight 370 continues, Brendan Koerner looks back at the motives of the hijackers of decades past in his new book “The Skies Belong to Us: Love and Terror in the Golden Age of Hijacking.” Koerner has been applying some of the lessons of the "golden age" of hijacking to better understand what might have happened on the mysterious, missing flight.