Sydney plane missed kids by seconds

A Piper Navajo similar to the one that crashed in Sydney yesterday. Photo / Supplied

It was a miracle that scores of children were not at ground zero when a light plane crashed next door to a school in Sydney's southwest and burst into flames, killing its pilot and sole passenger.

Canley Vale Public School principal Cheryl McBride was 20 seconds from serious injury or death when the Piper PA-31P twin engined plane smashed into the front yard of a house about 10.10am NZT on Tuesday.

Pilot Andrew Wilson, 27, and nurse passenger Kathy Sheppard, 48, died at the scene.

Mr Wilson had declared an emergency just 20 minutes after take-off from Bankstown Airport and was returning from the Richmond area before the plane went down about 5km from the runway.

Next to the crash site is a school driveway that teachers use, and which students cross on their way to school.

Ms McBride was just 150m away in her car when the plane struck a power pole and exploded on impact.

"Had I been 20 seconds earlier it would have been different matter for me or for another teacher waiting to go into that driveway," she told AAP.

She was also amazed that no one was closer to the crash site.

"You'd literally have up to 50 children at a time walking along that road, waiting to cross over," Ms McBride said.

"Even at five past eight in the morning I am still stunned that there was not a teacher or a family seriously injured or in fact killed."

Teachers in the vicinity grabbed every child they could and rushed them to the back of the school, Ms McBride said, before emergency crews evacuated everyone to a nearby park.

"The absolute fortune and luck and timing is just incredible," she said.

NSW Premier Kristina Keneally expressed her condolences and hoped witnesses were coping with the experience.

"This is a truly tragic incident and my thoughts are with the families (of those killed)," Ms Keneally told reporters in Sydney.

"And it certainly would have been distressing for those people who witnessed the accident, particularly young children who witnessed or were involved in the accident."

Seven people, four adults and three children, were taken to Liverpool Hospital suffering emotional distress after witnessing the explosion.

Ms Keneally would not pre-empt the Australian Transport Safety Bureau's findings and refused to comment on media reports that safety standards at Bankstown Airport were substandard.

The safety bureau expects to release a preliminary report on the crash in 30 days after examining official automatic voice recordings from Air Services Australia and weather conditions at Richmond.

Asia-Pacific Aerospace Report editor Peter Ricketts said the ATSB might have difficulty determining the cause of the crash.

"How they'll ever sort out that stack of molten metal is beyond me," Mr Ricketts told AAP.

He also said it would be rare for both engines on a plane to fail and did not rule out a possible fuel problem.

"It is very unusual ever to see an aeroplane with real engine trouble," Mr Ricketts said.

On Wednesday, the school held a general assembly of students and made counselling available to those affected by the crash.

- AAP