The Duchess of Cambridge, Kate Middleton, proves that you can still stay classy and regal, even when mingling with the "common folk".

On Tuesday, passengers of British Airways flight 7:15 from Netherlands to London were pleasantly surprised to learn they had a famous co-traveller on the plane - the Duchess of Cambridge, Kate Middleton.

Following in the footsteps of the late Princess Diana as "the People's Princess", Kate is showing the same practicality and unassuming air by flying commercial instead of chartering expensive private flights, endearing her to royal watchers around the globe.

As reported by the Daily Mail, she was still in the same light-blue Catherine Walker skirt suit she wore throughout the day during her first official royal trip abroad, unaccompanied by her husband the Duke, Prince William.

She had a busy day, first paying a courtesy call to King Willem-Alexander at Villa Eikenhorst, then touring the Mauritshuis museum in the Hague. She later joined a discussion at the residence of British Ambassador to the Netherlands, Sir Geoffrey Adams. Her last visit was to the city of Rotterdam before boarding the flight to go home.

She boarded the plane at the last minute, escorted by her bodyguards and staff. There were no diva-like behavior or ridiculous demands, the only special concessions the princess was given was priority seating on the front of the plane, and being allowed to disembark before the other passengers.

Fellow passengers, who were understandably bedazzled and starstruck, scrambled to get a picture of the princess as evidence of their experience.

This is surely not the first time Kate has flown commercial before, as she was a "commoner" before she married into the Royal Family. As a matter of fact, Yahoo!Mail reports her parents, Michael and Carole, both worked as flight attendants for British Airways.

This is also not the first time the members of the Royal Family, the Duke & Duchess in particular, has flown commercial. Prince William also took an American Airlines commercial flight from Memphis to Dallas in 2014.

On 2011, the royal couple also flew on a British Airways flight from Los Angeles to London.