The Duke and Duchess of Cambridge flew their family on economy airline FlyBe for transport to the family's Balmoral residence on Scotland's east coast.
The unusual mode of transport for the Royal Family comes just days after the Duke and Duchess of Sussex Harry and Meghan were met with raw criticism of their overreliance on private aircraft.
The couple – who advocate for sustainability and ecology-based activism – were berated for the use of a private jet twice within the same week for trips to Ibiza and Nice for the Duchess' birthday.
Environmental campaigners accused the pair of hypocrisy, saying that Harry and Meghan's actions contradict their public stance on climate change, given aviation is one of the world's major polluters and is responsible for more than 2% of global emissions.
The environmental footprint of a private jet is also much greater than that of a commercial plane.
According to CNN, prices for the route William and Kate took with their children start at £73 (€80.64), with a fully flexible fare costing £249 (€274.89).
A Flybe spokeswoman said: "We were delighted to welcome the Duke and Duchess of Cambridge and their family onboard one of our flights again, this time when they flew from Norwich to Aberdeen on a Flybe flight operated by Eastern Airways."
Kensington Palace declined to comment.
Earlier in the week, Sir Elton John, Pink and Ellen Degeneres defended both Harry and Meghan's private jet use, citing the press reaction as a “relentless and untrue assassinations on their character.”