Prince William has taken a budget flight to Scotland, following the public furore over his brother's private jet trips.
Prince Harry and his wife Meghan flew to Ibiza for six days to celebrate Meghan's 38th birthday. They returned to England for two days before jetting off to the French Riviera.
The tabloid press slammed the couple's flights after their repeated advocacy of environmentalism to fight climate change.
Now it seems the controversy has affected William.
William was spotted getting off a £73 (NZ$140) FlyBe flight to Scotland on Thursday (local time) along with his wife Kate, their nanny and their three children George, Charlotte and Louis.
It's believed they were on the way to visit the Queen at Balmoral in Scotland. Royal watchers speculate the flight is another sign of ructions between the royal couples.
"It's a shrewd move by the Duke of Cambridge and great for the public," royal author Robert Jobson told the Daily Mail.
"They get to see the heir to the throne and his children who are next in line, and if they can fly budget then surely Harry, Meghan and their child are able to as well."
A witness on the flight told the Daily Mail nobody recognised the Duke and Duchess at first.
"They weren't harassed by anyone at all as they got off the plane. They just seemed like a family travelling together, to be honest.
"No one saw them get on the plane either. It was amazing how they did it - they must have slipped on quietly after people were already seated."
Kensington Palace refused to comment on the matter.