The Duke of Cambridge played at being a First World War fighter ace when he got the chance to see some historic aircraft from a bygone era.
William clambered into the cockpit of a replica British bi-plane and looked down Its machine gun sight as Kate watched.
The royal couple were visiting the Omaka Aviation Heritage Centre in Blenheim, New Zealand, and toured the Knights of The Sky exhibition - Lord of the Rings director Peter Jackson's display of First World War aircraft.
Outside the tourist attraction a number of planes were lined up on the grass from the First and Second World Wars and the royal couple were led over to the aircraft.
William, 31, was invited to climb into a German Fokker tri-plane but turned down the chance out of patriotism, saying: "I'm not climbing into a German plane but I'll get into that Sopwith."
The royal couple headed to a replica Sopwith Pup, a bi-plane that would have been flown by British pilots during the Great War.
Built in the 1960s it was designed to look like the plane used by New Zealand flying ace Malcolm McGregor, awarded the Distinguished Flying Cross and bar and credited with downing 10 enemy aircraft and an observation balloon.
William climbed on to the wing and as he swung a leg over to squeeze himself into the small cockpit, the nearby dignitaries laughed.
Jackson, who had shown the royal couple his collection of planes and memorabilia from wartime pilots filmed everything on his smartphone.
William, a former RAF Search and Rescue helicopter pilot, could not contain his excitement and said "Start her up", but the plane stayed firmly on the ground.
Kate, holding an umbrella against a light drizzle, peered over her husband's shoulder and he talked her through the controls of the aircraft.
When it came to the moment he had to heave his tall frame out of the cockpit the Duke joked: "Now to get out of here, there's no dignified way to do this."
The royal couple had more room to manoeuvre when they climbed inside a Second World War Avro Anson Mark 1 bomber, the only surviving airworthy example in the world.
Inside the museum, the royal couple were presented with a child-size flying helmet, lined with possum skin, for Prince George.
Jane Orphan, chief executive of the attraction, said: "We were very keen to mark the occasion with a gift and this is all about preserving the heritage for future generations, we thought what better to give than a gift for the young prince."
Peter Jackson, New Zealand's most famous film maker, has been collecting First World War memorabilia since he was 12 and could not hide his enthusiasm showing the royal couple around the inside of the museum, which contains 20 of his planes displayed on dioramas depicting dramatic scenes from the conflict.
One scene featured a plane that has crashed into a tree made from the same material that created the Ents in his Lord of the Rings trilogy.
Kate, 32, was fascinated to see the mannequins of pilots sitting in open cockpits, she said: "They must have been freezing."
The royal couple were introduced to the museum's senior guide, Harcourt "Bunty" Bunt, 93, a celebrated Second World War Spitfire pilot from Picton, who explained one of the most daring escapades depicted in the museum.
The diorama showed New Zealand's highest scoring ace of the First World War, Lieutenant Keith Logan "Grid" Caldwell standing on a wing and guiding his stricken plane down from 7,000 ft after a mid-air collision in September 1918 before jumping off seconds before it crashed.
Mr Bunt said: "He just brushed himself down and walked away. The plane was a write off."
Kate asked: "Did he ever talk about his experience later?" while William said: "I bet he dined out talking about it for several years," adding "Wow, what a story."
The director said: "This is a hero's story. Boy's Own stuff."
The royal couple were also shown a scene depicting the moment in April 1918 when the most famous flying ace of the First World War, the Red Baron, Germany's Manfred von Richthofen, met his death after crashing his red triplane into a beet field surrounded by Australian infantrymen who then stripped the plane for souvenirs.
The plane is a replica but the original German cross, stripped from the side of the plane by the troops, is in the museum.
A member of the host delegation joked: "These are Australians as well. New Zealanders would never do this."
Outside, William and Kate met two young fans, sisters Tallulah, nine, and Eloise, seven, Debinette from Blenheim, who gave Kate a posy and William a picture from his visit to Auckland in 2010. The framed picture showed William meeting Tallulah.
Their mother Sara-Lee Debinette said to the Duke: "You told her she had piano fingers," and he replied: "I never did, I'd never say such a thing."
The aircraft enthusiasts who run the heritage centre, which opened with the help of £1 million from the New Zealand government in 2006, now attracts 30,000 visitors a year.
Graham Orphan, one of the trustees who showed the couple around outside, said they seemed to have enjoyed their visit: "It was fantastic. He is such an aviation enthusiast. It was great to talk to him."