This year a team of four air force personnel made up of a team leader, two vehicle mechanics and a medic will provide a mobile vehicle workshop and medical aid to entrants and their pre-1975 cars.

Two of those will be flight sergeant Tony Perry and mechanic leading aircraftman Phil Webb, both from RAAF Base Williamtown.

Flight sergeant Perry, a bash rookie, said his mates had taken part in previous events and all had come back with fantastic stories of their trips.

"I'm excited to help out the Bash teams any way I can," he said.

"I'm also looking forward to visiting local schools and charities along the route, and kicking a football with the kids."

For leading aircraftman Webb this will be his second Bash.

"I love the concept and I enjoy fixing the Bash cars," he said.

Flight sergeant Perry said the Bash was a great opportunity for all involved, but especially for the vehicle mechanics.

"The mechanics really need to think outside the box, as most of the time you're out bush with only basic equipment," he said.

Departing from the Sydney's Balmain on August 26 and travelling 4000 kilometres north to Bamaga in Cape York during the 10 days, the annual charity drive raises funds for Variety - The Children's Charity, which helps children with special needs.

Every year Variety provides more than $12 million to assist 45,000 special-needs children and their families.

The air force's association with the Variety NSW Bash dates back to 1990, when it entered a team driving an HR Holden station wagon.

It also provided two mobile workshops.

For more information about the bash or to donate visit www.variety.org.au/NSW/Events/Bash/ .