I never thought of a plane name when I heard the song. I think it refers to the upheaval in American society in the coming decade. We went from Beaver Cleaverto Eldredge Cleaver in less than a decade. The White bread America of the 50s gave way to the sexual revolution of the hippie era.
Yeah, girls had premarital sex in the 50s, but it was hushed up, swept under the rug, and if she got pregnant, she was sent to a school for wayward girls and delivered her newborn. Then, more often than not, she was forced to put the baby up for adoption. But girls were assumed pure at that time. With the free love movement, that changed. He's saying goodbye to the loss of innocence of the era.
At least, that's how I've interpreted it for the last 45 years.