Last year, Kate, William and their children arrived in Scotland after taking an economy flight to the royal property.
This undoubtedly would have startled the other passengers, after seeing the future King and Queen of the United Kingdom travel on the same flight.
The royal custom of spending the last few weeks of the summer break at the opulent highland residence has a long history that dates back to when Queen Victoria bought the estate.
Last year, two of Princess Kate’s three children, Princess Charlotte, eight, and Prince Louis, four, were seen accompanying her as she descended from her flight, according to a TikTok user.
The Prince of Wales and his eldest child Prince George, 10, travelled separately.
Two heirs to the British throne should never travel together, according to royal tradition.
But William appears to have disregarded this rule several times since Prince George was born.
According to the passenger last year, Kate did what every normal mother would do on a flight with her children.
The TikToker said: “[Kate] got up halfway through the flight to get her daughter’s iPad.
“And yes she was stunning, even gave me a smile while looking back at the row behind her to talk to her son.”
Kate’s stylish ensemble was very casual, which made sense due to her informal means of transportation.
For the flight, she layered a sage green midi skirt with a khaki blazer.
Princess Charlotte wore a long-sleeved floral dress that made her look just as stunning. In addition, her honey-coloured hair was neatly plaited.
Prince Louis, meanwhile, wore a blue shirt and navy fitted shorts.
Many royals travel with monogrammed bags, showing that this is another precedent set for royal air travel.
Princess Charlotte was seen with a monogrammed bag, similar to her father, who was photographed in 2011 travelling to Australia with luggage bearing the letter W and a crown.