This American Life had a segment that was someone telling a story about when they were a teenager and snuck onto a domestic flight.

"Act Three" here: https://www.thisamericanlife.org/477/getting-away-with-it

So, I dunno, I can believe it, although I don't know exactly how connections worked then or if it could have been the same plane stopping in LA and continuing to Japan or what. But in general, yeah, "security" wasn't actually a thing on planes then. There was no security checkpoint at all to get to a gate before the 70s; you didn't need a ticket or to show ID to go through the security checkpoint that did exist before 2001. It's easy to forget or not realize how much thing have changed.

Or, it's just one of those rumors that people like to adopt and claim as a story that happened to htem, when really they heard it from someone else that claimed it happened to them, etc. That also happens.

That's the beauty of a good story. Someone can share something outrageous and the audience can enjoy the tale while the reality is "protected" by that looming doubt of whether it really happened or not. :p

I know that it is a little hard to believe but back in the sixties before hijackers changed the rules flying was a whole lot more relaxed. No security, just walk out on the tarmack, climb the steps and you're on the plane.

It was like a ship, friends could accompany you and then leave when they asked for all guests without a ticket to depart. I was just a kid but I do seem to remember them checking tickets. But I suppose you could wander aboard and find a good hiding place, unlikely but not impossible.

Flying domestic from Whangarei to Auckland isn’t much different today :) they check tickets and your bags get scanned of course, but it’s an extremely pleasant experience. The flight is fun too, prop planes!