People have one question after finding out Prince George is about to be separated from Prince William and Princess Charlotte

It's only a matter of days away now until Prince George will start needing to be separated from his family members when it comes to one very specific situation.

Next week (22 July), Prince William and Kate Middleton's eldest child and second-in-line-to-the-throne, George, will be turning 12 years old and, if the family follows royal tradition, he could be forced to travel separately on royal visits and tours.

Some were confused about the rule, namely wondering if George would also be separated from his mum, Kate, and his two younger siblings.

One social media questioned: "What about being separated from his mum?"

"Not his mum and brother?" asked another.

The royal family are set to carry out a decades-old tradition following Prince George's 12th birthday next week (22 July) (Tim Clayton / Contributor / Getty Images)

Well, it's actually only William he has to be separated from according to the rules.

This is because William is the first in line to the throne and the rules would mean that the two royal members in succession can't be together.

The tradition was put in place in case the worst should happen and a plane crashed, it would mean an heir to the throne is protected and keeps the monarchy stable.

That's not to say he also won't be travelling with his siblings, Princess Charlotte who is third-in-line and Prince Louis who is fourth-in-line - but that's apparently down to the family's discretion.

The rule only covers heirs, so he could still travel with his mum, Kate.

While the rule is unwritten, such precautions are heavily advised, especially after Prince Philip's sister Princess Cecilie died in a plane crash in 1937, five years before Queen Elizabeth II's uncle Prince George was killed in the same way.

Such was also the case for the late Queen's cousin, Prince William of Gloucester, in 1972.

Two royal members in succession reportedly can't fly together in case the worst should happen and a plane crashed (ANDREW MATTHEWS / Contributor / Getty Images)

When William turned 12, he was no longer allowed to fly with his father, King Charles III, nor his younger brother, Prince Harry.

Speaking previously to OK! Magazine, Charles's former pilot, Graham Laurie explained of the practice: "We flew all four: the Prince, the Princess, Prince William and Prince Harry, up until Prince 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 Her Majesty.

"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."

Now, whilst the decades-old tradition is somewhat undocumented, apparently, it's up to the reigning monarch on whether it can be broken.

So, if William and George did want to continue flying together, they'd have to ask Charles for permission to do so.