Aviation experts from Oxford University fear expansion at Gatwick airport will end in disaster.

They say planes which over-run a new runway could end up on the main London to Brighton railway line.

And they have highlighted other safety fears in their study entitled Gatwick - Why A New Runway Won't Work, which has been sent to all MPs and senior civil servants.

There are three expansion options on the table.

They are a full-length runway to the south and parallel to the existing one; a full-length runway about 1,000 metres to the south of the existing one; or two new runways, one to the south and one to the north of the existing one.

The report has been drawn up by the Aviation Study Group (ASG), of Linacre College, Oxford, which has been advising people in the aviation industry for more than ten years.

It was commissioned by the Gatwick Area Conservation Campaign (GACC), which is fighting the plans.

The report highlights potential dangers of turbulence if a second runway is created and says the layout would be "cramped and convoluted".

Schemes put forward would create inefficiency and "potential danger", according to the report.

The ASG said a proposed northern runway could create turbulence, while a southern runway could create dangers of a vortex in the air and would be very close to the main London to Brighton railway.

Derek Dempster, of the ASG, said: "One of the proposed new runways would go through a hill.

"We are concerned by the problems of turbulence to aircraft flying through the cutting.

"If you are on a bicycle and a bus goes past you can feel the wind pulling you over.

"Turbulence is caused by all sorts of things and can vary according to the direction of the wind.

"Also there are vortices. An aircraft can create tremendous movements of air and those following behind could be affected. This is sometimes a hazard.

"There is also the possibility of over-runs and in the case of an aircraft over-running there is the chance of it going over the railway."

The group also highlights problems of taxiing between the runways and the terminals.

Mr Dempster said: "In the USA there have been a number of major accidents caused by aircraft taxiing on to an active runway in error. Any expansion of Gatwick, especially if it goes to three runways, will create very substantial risk."

A legal agreement between West Sussex County Council and the British Airports Authority rules out any expansion of the airport before 2019.

Brendon Sewill, chairman of GACC, said: "These safety issues, and the subsequent inefficiencies, rule out any new runway at Gatwick, whether before or after 2019.

"Last year, the Government ruled out any new runway at Gatwick for the next 30 years and we expect that decision to be confirmed in the forthcoming White Paper."