Yesterday, he celebrated 20 years since the operation with a tandem hang-glide off Bald Hill.

The 47-year-old from Belfield in Sydney is the longest surviving double lung transplant recipient in Australia.

He received the transplant because he had cystic fibrosis.

"It's really the only way you can survive it - it's a lethal disease. By the time you reach your 20s your lifespan is pretty much over."

The surgery was experimental 20 years ago, leading doctors to think it might give him another year. Mr Leggett said that, since the transplant, he had approached life a little differently.

"It's a case of you don't know how long you've got so you just live your life the best way you can and pack as much into it as you can," he said.

So many things in fact, that he chose to mark the 20th anniversary by hang-gliding because he didn't have much else left to do.

"Well, I've done a lot of the other things," he laughed.

"I've done parachuting, I've done whitewater rafting, I did stand-up comedy once. So I've done a lot of the other scary stuff, so I just wanted to tick another one off.

"Stepping off the cliff is a bit frightening but once you get up there it's just amazing," he said.

"You don't realise just how fast you're going and you take in the view - it's beautiful."

As you'd expect, Mr Leggett is a big supporter of organ donation.

"An anonymous person donated their organs to me 20 years ago," he said.

"I never knew the person and it saved my life. So I always try to promote organ donation in the community."