Britain's Duchess Catherine took a £3,000 helicopter flight home from London.
The Duchess of Cambridge made a return trip between London's Kensington Palace and her family home of Anmer Hall in Norfolk - which was 110 miles and took just 45 minutes each way - on February 7, a day before Queen Elizabeth made a similar journey from Norfolk to London by train at a cost of just £54.90.
A Kensington Palace spokesman told the MailOnline: "The Royal Household makes careful decision about transport plans and always seeks to travel in the most appropriate way possible considering the arrangement for an official engagement."
Catherine took the Queen's Flight - used by royal family members on official engagements - from Anmer Hall to Kensington Palace in order to attend an 11am service in London to mark the 75th anniversary of the Air Training Corps, her first engagement as its Honorary Air Commandant.
She then changed clothes before flying back to Norfolk at around 1pm.
Royals are permitted to take flights between residences according to Buckingham Palace's visits committee, but the queen regularly chooses to travel to and from Sandringham - where she has been staying since late December - by train.
The queen had boarded the 10.54am train from King's Lynn station - the nearest to Sandringham - to King's Cross, arriving in the first class carriage five minutes before departure.
Station manager Graeme Pratt said: "It's an honour to have her use the train service. I asked her if she enjoyed her stay in Norfolk, to which she said she did."