What about the incident with pop duo "The Cheeky Girls" gaining access to the flightdeck, after the captain invited them.
Apparently, according to The Sun, the aircraft then started "going all over the place" in the words of a passenger.
The airline was KLM, the aircraft was a Fokker Twin Prop with 100 PAX onboard at the time. Both pilots may be fired for misconduct.
Quite rightly so - and besides - I doubt that two singers who earn a living by shaking their bums while signing are interested in how an aircraft is flown, but rather some little boy up the back who wants to be a pilot could gain a lot more from the experience.