The FAA is investigating a  Harlem Shake video that's big on YouTube right now where an entire AIRPLANE full of people do it.

It was recorded over President's Day weekend, and organized by a bunch of college students who were on their way to an Ultimate Frisbee tournament in San Diego.

They claim they asked the flight attendants for permission first.  And the FAA apparently just wants to make sure it didn't take place during takeoff or landing.

Check it out here: