Airplane Poop

I'm very proud of Evelyn for wanting to go potty by herself today. When she came back (I was on the phone) she told me she went poo and gets num nums! Then, as we're walking to the bathroom for the num nums she tells me she had an airplane poop. I was very curious what that was and if I even heard her right but again she told me she had an 'airplane poop' followed with hand motions and airplane sounds. "Vrrrrrrruuuummmm!" I have no clue where she got that from or what it actually is, but she seems to know and that's what matters.