Slatz--I don't know where the image of the planes originated. I've used it as long as I can remember--to me, at least, it's a pretty vivid and accurate image. I suspect it first occurred to me when I was demonstrating "skiing" with my hands--flying them through the air like...a couple F-16's! This is something I do often too--if we can teach our hands to do something, it helps in transferring the movement to the feet. And if we CAN'T do it with our hands, there's little hope....
I am a little more reluctant to use it these days, though, since a fighter pilot I had in a Mahre Training Center group at Keystone maybe 10 years ago tried to explain that it's not EXACTLY the way fighters fly. Something about one going up and one down, in a pattern more complex than meets the eye. I never understood it. I've skied since, though, with many fighter pilots, and none of them has seemed to have a problem with my simplified image. If it isn't technically correct to a pilot, at least they've been willing to overlook the details and see the point!