Prince Philipfamously gave up a promising naval career to be at the Queen’s side – but the Dutch King Willem-Alexander has carried on co-piloting KLM passenger planes as often as twice a month.

According to an interview he gave to the Dutch Telegraaf paper, to celebrate his wife Queen Máxima’s birthday on Wednesday, flying through the clouds leaves worldly cares behind, so he has quietly carried on.

He welcomes customers on board “on behalf of the captain and crew” – rather than revealing his true identity – and said he is rarely recognised in pilot’s uniform anyway.

Willem-Alexander became Europe’s youngest king when Dutch Queen Beatrix abdicated in 2013, in a ceremony attended by Prince Charles and Camilla, Duchess of Cornwall.

It was known that he had been a “guest pilot” before being crowned to keep up his pilot’s licence on the Fokker 70 aircraft, and the Dutch public information service announced in 2013 that he planned to maintain this status “for as long as possible”.