The 'autopilot' scenes in Airplane!, if I remember them correctly (and I may not --it's been years since I saw that movie), were not that obvious. IIRC to a small child, it would've just looked like a silly balloon toy flopping over.
Even though as I said, I wouldn't show that movie to little kids, I doubt a small child would've picked up what was going on there --unless, of course, that child had already been exposed to a hypersexualized environment. (Say, oh, hearing about Bill Clinton's romantic exploits, for example.)
OTOH, here's what my children would've been asking me about First Lady's jokes, if they were still little:
- Mommy, what does she mean, "Dollar Bill Lynn" ?
- What's a chippendale, mom?
- Mom, what's "Desperate Housewives" about? Can I watch it? Pleeeeeeeease?
- Mom, how do you milk a male horse?
So I told him: "It's pictures of adults without their clothes on. Sometimes they're being romantic. Some adults like looking at them."
"Oh. I thought it might be something like that."
< very stern voice >"You do realize that it's for adults only."< /very stern voice >
"Daddy, I'm a kid! I'm not interested in that romantic stuff."
Not the easiest bit of parenting I've had to do, but I was quite satisfied with it.