A young pilot is in a coma after his light aircraft crashed into the roof of a house yesterday, minutes after taking off from Brisbane's Archerfield airport in Queensland, Australia.

Blue smoke billowed out of the four-seater Cessna 182 as the 29-year-old pilot attempted to make an emergency landing in a park in the southwestern suburb of Darra.

Police believe the single-engined plane clipped power lines on its descent before slamming into the roof of the two-storey house at 11.20am and landing upside down in the backyard.

Resident Brett McDonald, 41, pulled the pilot from the plane just before the burning wreckage exploded.

He said the pilot then walked by himself through his garage, sat down in his driveway and waited for an ambulance.

The pilot, who was en route to his home town of Goondiwindi, on the NSW-Queensland border, suffered burns to his arms, legs and respiratory system. Last night, he was in a medically induced coma in the Princess Alexandra Hospital.

Oxley police superintendent Keith McDonald said the pilot had told doctors he had climbed to 1000ft after takeoff before experiencing engine problems.

He credited Mr McDonald with saving the life of the pilot by pulling him from the burning wreckage.

Yesterday, still shocked after the unexpected explosion in his backyard, Mr McDonald said he was downstairs when the plane slammed into his roof.

"I first saw a big shadow coming over, blocking the light coming in my window, and I thought that's a pretty big shadow," he said.

"Then there was a huge bang.

"I went out the back just to see if something fell on the roof and saw a plane in the backyard on fire, so I went around to the side to see if there was anyone in there, saw him and went around the other side, and he was sort of trying to get his way out."

Mr McDonald's 12-year-old daughter received a minor wound to the head from a falling ceiling.

Four months ago, another light aircraft pilot attempted to make an emergency landing in the densely populated suburbs near Archerfield airport.

John Savina, 51, of Townsville, was killed instantly when his two-seat, single-engine Lancair 320 aircraft nosedived into a gully at Coopers Plains in Brisbane's southwest, just metres away from a busy road.

Despite two crashes in suburban Brisbane this year, the federal Transport Department said it would not consider relocating general aviation airports such as Archerfield to less populated areas.

"It's an issue that arises when there's an accident of this type and no one likes to seeit," a spokesman forfederal Transport Minister Warren Trusssaid.

"But generally, the benefits of having light planes and giving them access to airports are seen as outweighing the risk."

The Civil Aviation Safety Authority yesterday supported the Government, saying it would be too costly to move airports such as Archerfield, and Bankstown in Sydney.

"A lot of the crashes are during takeoff and landing - in other words around aerodromes - but the level of (overall) risk is not that high," a CASA spokesman said.

Over the past 10 years, 321 people have died in civil aircraft crashes in Australia.