Updated

The king of the Netherlands has revealed he has been living a secret double life as a co-pilot for a commercial airline.

For 21 years, King Willem-Alexander has taken to the skies twice a month to ferry passengers around on short-haul services for the Dutch airline KLM.

Although travellers may have recognised the monarch's voice as he updated them on weather conditions and their time of arrival, the royal's presence was never revealed.

The fleet of smaller Fokker 70 planes flown by the king are now being phased out by KLM, meaning he needs to take time out to retrain and learn to fly Boeing 737s.

The 50-year-old royal described his casual flights as a "hobby" - and said occasionally being able to leave his royal duties behind to concentrate on flying was "relaxing".

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