http://www.abc.net.au/news/newsitems...5/s1374692.htm

yowie!

Plane's vortex raises a roof

A house under Sydney's flight path lost two-thirds of its roof tiles on the weekend when a plane flying overhead created a vortex.

Peter Smith was walking past the home on Unwins Bridge Road in Sydenham on Saturday afternoon.

He says he heard a plane and then saw what looked like a tornado lifting roof tiles half-a-metre into the air.

"It was the vortex, it was extremely loud," Mr Smith said.

"I thought, this is going to be interesting to see where it hits and all of a sudden the tiles started jumping in the air and flying off."

Investigation

Civil Aviation Safety Authority (CASA) spokesman Peter Gibson says the organisation is investigating the incident.

"You hear about this occasionally, particularly in Sydney, but not very often," he said.

"We'll want to look at it from the point of view of was that particular aircraft or any other on that weekend flying below the altitude they should have been.

"Beyond that of course, the exact connection between the aircraft and the tiles falling off needs to be explored further."

Mr Gibson says he does not know what else might have caused the tiles to come off if an aircraft was not responsible.

He is urging anyone who has information to contact CASA or the federal Transport Department.

'Conditions right'

A spokesman for Airservices Australia, Richard Dudley, says conditions on Saturday were right for a vortex.

"There were very light winds, that is what we call wing-tip vortex or turbulence and that appears to be the case on that particular occasion," he said.

"We get that about three or four times a year on average."

He says vortex incidents are obvious from the tell-tale zipper pattern of the damage.