Floating vomit

How better to grasp the dynamics of a flying airplane than to actually experience them? Dozens of students went up in the air in recent weeks with the TU Delft research airplane.

The classroom at 4000 feet. (Photo: Tomas van Dijk)

“The military wants to do some kind exercise with F16 fighter planes,” says pilot Dr Xander in ’t Veld. “That’s why we have to go further to the east, all the way to Twente. Hmm…they’re really sending us far away.”

Finally the Cessna citation research airplane (owned by TU Delft and the National Aerospace Laboratory) is flying in a military zone where the pilots are allowed to do all kinds of caprioles. The five students (from AE faculty) on board all have a computer screen in front of them that provides information about speed, position of the rudders, flaps and the various forces at play.
“Of course you can study the behaviour of a plane by solving differential equations,” says In ’t Veld. “But once the students are in the air the penny drops. Here they really get to grasp the dynamics.”

In ’t Veld’s explanation about the importance of this yearly practical course for AE students is suddenly interrupted by his colleague, pilot Hans Mulder. “Okay, we’re stationary again guys”, he shouts. “Gogogo…” The students all start making notes.
When asked if he sometimes plays tricks on the students, Mulder replies that he and his colleague are “not fooling around in the air”. Whereupon he warns me that I should get hold of something. “Yes,” says In ’t Veld, “we’re about to mimic the situation which caused the crash of the Turkish Airlines plane a while ago. Don’t worry, at this altitude nothing can happen to us.”

The students, with bright smiles on their faces, are clearly pleased with what is about to happen. As the pilots reduce speed the air flow separates from the wing and the plane starts shaking heavily.
“It’s cool to see that what we learned in theory is correct,” says student Tim Neefjes. “The coolest thing about this practicum however is the parabolic flight where you come to be in a condition of weightlessness.”
Unfortunately that state is not meant to be on this specific flight, as one of the students gets sick a little later during the spiral plunge. “Too bad,” says Mulder, “I don’t want to make the parabolic flight with a bag of vomit floating around in the cabin.”