Prince George and Princess Charlotte have inherited this expensive passion from Prince William

Kate Middleton has revealed one of her children's favorite interests—and they just so happen to share it with Prince William. 

• Kate Middleton revealed a favorite interest of her children during her most recent public engagement, much to the delight of royal followers. 
• Prince George and Princess Charlotte are all big fans of a unique—and expensive—hobby, and it looks like they can thank Prince William for sharing it with them. 
• In other royal news, the Queen set to miss ‘unique event’ for the first time in 16 years.
  

Kate Middleton made her first appearance in two months this week, marking the official end to her relaxing summer break with husband Prince William and their three adorable children. 

She kicked off her autumn working calendar with a visit to a Royal Air Force [RAF] base outside of London on Wednesday, where she met with the courageous troops who participated in the UK's evacuation of citizens from Afghanistan. 

Wearing a gorgeous Reiss blazer paired with wide-legged navy trousers, the Duchess of Sussex spoke with RAF aircrews and medics at Brize Norton about their mission to rescue people from Kabul Airport in the wake of the Taliban's swift takeover of the wartorn country. She also was introduced to the volunteers who set up a repatriation center for incoming refugees. 

With George and Charlotte back in school uniform and Louis at nursery, Kate didn't have any childcare duties during the engagement. However, that didn't stop her from thinking about her kids. 

While Kate has long been praised for prioritizing her children's privacy, she's also not afraid to share the occasional snippets about their personal lives. In the past, she's revealed Princess Charlotte's favorite food and posted sweet photos of the royal tots on their birthdays. It looks like she's now treated the public to another piece of information about their inner worlds—their hobbies. 

At one point of the tour, Kate let slip a nugget of intel about her children's pastimes, implying they'd probably have loved to have accompanied her to the RAF station. 

"She did mention that her children are very interested in aircraft," Lordmaster Sergeant Mark Curtis told PEOPLE magazine. This expensive and time-consuming activity is likely out of the question for regular kids, with introductory flying lessons costing a minimum of $120 a pop. 

Luckily for George, Charlotte, and Louis, their father—who has plenty of experience with flying—is very likely to encourage them to pursue the hobby. 

The Duke of Cambridge famously served as a search and rescue pilot in the RAF [Royal Air Force] from 2015 to 2017, and reportedly still practices the skill in case he is needed in the emergency services again in the future. It's even been rumored that the Queen had a $5.4 million helicopter landed at his pad in Amner Hall so that he could clock up the hours required to maintain his air transport license.