Prince William, who’s so far free to fly with his three young children as they are small, may not be allowed to travel abroad alongside his eldest son Prince George in the years to come.

There are several rules exist to protect the King and other members of his family when they fly overseas, some of which are truly surprising, and one particularly unique one comes into play when any young heir to the throne turns 12.

King Charles’ former pilot Graham Laurie, speaking on HELLO Magazine’s ‘A Right Royal Podcast’, explained how the rule affected a young Prince William when he turned 12 in 1994.

“Interestingly, we flew all four: the Prince, the Princess, William and Harry, up until  William was 12 years old. After that, he had to have a separate aircraft and we could only fly all four together when they were young with the written permission of the monarch,” Graham told the hosts.

The former royal pilot added: “When William became 12, he would fly normally in a 125 from Northolt and we would fly the 146 out with the other three on.”

William’s ten-year-old son Prince George, second to line of succession, will also be affected by this rule and he will be expected to fly separately from his father when he reaches to a certain age.

It remains to be witnessed if Prince Louis’s elder brother George will follow the rule. The unique restriction is in place to protect the heirs to the throne. 

However, the rule can be broken with the monarch’s permission, it is discouraged to have two or more direct heirs travelling in the same plane as in the event of a crash, the future of the monarchy would be immediately unstable.