A blind aviator is aiming to fly halfway around the world to raise £1m to help prevent blindness.
The 100-horsepower microlight has a top speed of 70mph
Miles Hilton-Barber, 58, from Derbyshire is hoping to become the first blind aviator in history to fly from the UK to Sydney.
His departure on Monday was delayed by bad weather - and he is now unlikely to leave for at least several days.
He will be accompanied by his sighted co-pilot Storm Smith in a specially adapted microlight.
He will fly in stages along the 13,500-mile route across Europe, the Middle East, India and Indonesia.
He will use speech-output technology to fly the microlight on the 45-day journey.
The money raised will go to Standard Chartered Bank's charity Seeing Is Believing, which is supporting the World Health Organisation's attempts to wipe out preventable blindness in developing countries.
Mr Hilton-Barber, who plans to launch his bid from Biggin Hill Airport in Kent, said: "Sight is a wonderful gift many take for granted."
His flight is the latest in a series of adventures which include climbing Mount Kilimanjaro, running an 11-day ultra marathon from the Gobi Desert to the Great Wall of China, completing more than 40 skydives and circumnavigating 38,000 miles round the world using 80 forms of transport.
His latest journey will be in a 100-horsepower microlight which has a top speed of 70mph.
"When I was 18, I could still see and I joined the Rhodesian air force, but they kicked me out saying my eyesight was not good enough," Mr Hilton-Barber said.
"Now, 37 years later, I have this incredible opportunity to fly halfway around the world. It means you should never let anyone else tell you whether you can live your dreams or not."
Co-pilot Storm Smith, who lives in Newcastle, said: "We are trying to help give people back their sight and if we can do that then we will be very pleased."