Next time you fly, there just might be a king at the plane's controls. Holland's King Willem-Alexander has just revealed he has been secretly flying planes twice a month for KLM for 21 years. His passengers did not know. The 50-year-old king got his military pilot's license in his twenties when he was in the Dutch Air Force. He developed a love of flying and became a commercial pilot. He talked about his secret life as a pilot in an interview with journalists. The king said he now wanted to upgrade his skills. He is back on an aircraft simulator to train to fly Boeing 737s.

King Willem-Alexander told reporters that flying meant he could relieve all his stress. He explained: "You have an aircraft, passengers and crew. You have responsibility for them. You can't take your problems from the ground into the skies. You can completely disengage and concentrate on something else. That…is the most relaxing part of flying." He said it was easy to keep his secret while flying. Very few passengers knew he was piloting their plane. He said: "I always…wish everyone a heartfelt welcome on behalf of the captain and the crew. I don't…say my own name."