The royal household is to take delivery of two new helicopters, as it committed itself to maximising use of the aircraft.

The new AgustaWestland AW139s will replace the current 15-year-old Sikorsky helicopters.

At a previous financial briefing in 2022, a source described the eco-conscious King, then-Prince of Wales, as “pretty allergic” to travelling by helicopter and said he would always “raise an eyebrow” and object when the mode of transport was suggested.

But the Sovereign Grant financial report published on Wednesday revealed the aircraft will arrive in 2024-25, with the plan approved by the Treasury.

A palace official suggested it made better financial sense to “sweat the asset” and make maximum use of the new helicopters.

“Helicopters are a very important tool in our travel resources,” the official said.

“They provide great flexibility. They enable His Majesty and members of the royal family to be to be seen throughout the length and breadth of the UK.”

Asked whether helicopter use should be reduced, the official added: “If you’re going to make an investment of that magnitude, then you need to sweat the asset.

“So, therefore, you need to maximise the utilisation of the aircraft otherwise you end up in a situation whereby a small number of visits, compared to the cost of running those assets, it does not does not make good financial sense.”

Almost £1.1 million was spent on 170 helicopter journeys made by members of the royal family in 2023-24 made up of trips costing less than £17,000 each.

The palace official said that given the potential environmental impact, an increased use of Sustainable Aviation Fuel (Saf) was “fundamental” to the household’s long-term, sustainable strategy, and would be enhanced because the new helicopters are able to operate with the maximum industry standard of 50% Saf.

A temporary Saf tank has also been installed in RAF Odiham, with a permanent one planned for 2025-26.

Helicopter travel has long been associated with the Duke of York who was dubbed Air Miles Andy because of his frequent flights particularly while he pursued his love of golf.

The Prince of Wales worked as an air ambulance pilot for the East Anglian Air Ambulance and served as a RAF search and rescue pilot.

His eldest son Prince George is said to have been fascinated with aircraft since he was a toddler.

Meanwhile, the King’s state Bentleys are being converted to run on bio-fuel within the next year, with a view to switching to a fleet of official electric cars in the future.

A Bentley state limousine was presented to the late Queen by the luxury car manufacturer for her Golden Jubilee in 2002.

There are said to be two in the royal fleet, with the custom-made vehicles painted a distinctive claret colour below the waist rails and black above – the official livery for royal cars.

They serve as one of the main forms of transport for state and ceremonial occasions.