The Duke of Cambridge played at being a World War I 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 World War I aircraft.

Outside the tourist attraction a number of planes were lined up on the grass from the two 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.