Kate Middleton, Prince William and family spotted arriving in Scotland on budget flight

The royals may be known for their lavish trips, but the Duke and Duchess of Cambridge surprised royal fans around the world with their most recent visit to Scotland.

Kate Middleton, Prince William and their family were spotted deboarding a budget-friendly airline that arrived in Scotland from Norwich on Thursday morning, presumably to join the rest of the royal family at Queen Elizabeth's Balmoral Castle in Aberdeenshire.

Videos published by The Daily Mail show the family-of-five being escorted across the tarmac after the plane had landed. Prince William is seen in the footage holding hands with Prince George while juggling his luggage, while Princess Charlotte follows behind. The duchess can be spotted walking with Prince Louis in her arms alongside royal nanny Maria Borrallo.

Travelers aboard the budget-priced FlyBe plane reportedly had no idea the royal family was onboard.

"The family were sat right at the front. I fly this route all the time and we were non the wiser. No-one knew they were on the flight," explained a passenger. "Later on I realised that Kate's mother was sat a few rows in front of me."

This wasn't the first time the royals have been spotted on commercial flights. According to the Daily Express, the Duchess of Cambridge traveled to St. Lucia with a baby Prince George on a British Airways jet in 2013. And in 2016, she surprised passengers aboard another British Airways flight while returning home from her solo tour of the Netherlands.

The Cambridges' trip on Thursday follows increased criticism of Prince Harry and Meghan Markle's most recent travels to Ibiza and Nice, France. According to reports, the couple used private planes for both of their vacations with baby Archie, although Elton John recently spoke out about funding the couple's most recent visit to his French residence.

For more on their travels, watch the video above.