oldie but a goodie
An Airbus 380 is on its way across Atlantic. It flies consistently at 800km/h in 30,000 ft. when suddenly a Eurofighter jet appears. The pilot of the fighter jet slows down, flies alongside the Airbus and greets the pilot of the passenger plane by radio: "Airbus flight, a boring flight isn't it? Take care and have a look here" He rolls his jet on his back, accelerates, breaks through the sound barrier, rises rapidly to height, only to stoop down almost to sea level. He loops back next to Airbus and aks" Well, how was that?" The Airbus pilot answers: "Very impressive, but now have a look here!" The jet pilot watches the Airbus, but nothing happens. It continues to fly stubbornly straight, at the same speed. After 5 minutes, the Airbus pilot radioed " Well, what are you saying now?" The jet pilot asks confused: "What did you do?" The other laughs and says, "I got up, stretched by legs, went to back of the flight to bathroom, got a cup of coffee & a cinnamon cake. How's that?"