One moment Jim O'Neill was enjoying the glorious view from his Cessna plane at 15,000ft. The next, he couldn't see a thing.

Rubbing his eyes, the solo pilot thought his sight had been temporarily hampered by the bright sunshine.

Then he suddenly realised that he had gone blind.

Helpless at the controls, Jim, 65, immediately radioed in a mayday alert and an RAF plane was scrambled.