Rutherford said yesterday he felt “pretty confident” he was ready for the challenge, as he posed for pictures in front of his Shark ultralight plane at Biggin Hill Airfield in London.

“It’s really exciting to think that really soon I’m going to do something incredible,” he told Reuters, adding he was looking forward to seeing, among many other places, the Sahara desert, the Congolese jungle and New York.

The teenager, who is currently at school in England, is due to take off from the Bulgarian capital Sofia on March 17 and expects to be gone for two to three months.

On Jan 20, his sister Zara became the youngest woman, at 19, to fly solo around the world, and also the first person to do so in a microlight plane, after a five-month, five-continent odyssey in her Shark ultralight.

Mack, whose parents are also pilots, said he had known he wanted to fly from an early age.

“The first time I actually touched the controls and flew was when I was seven… since then, my passion has grown,” he said.

Zara said she was not planning to visit her brother during his journey, but would “be with him every step of the way”.

“He’s a great pilot and I know he’s able to do this,” she said.

Their father Sam echoed her confidence while acknowledging the risks of such a journey. “I think what he already has is an enormous depth in terms of his ability, not just as a pilot but as an aviator,” he said.

Mack said setting a new world record was not his main motivation. “I want to show that young people can make a difference… that you don’t have to be an adult to do incredible things.”

The current world record is held by Briton Travis Ludlow, who was 18 when he completed his trip.