NERVOUS fliers, strapped into their seats awaiting take-off, will struggle to dislodge the image. On closing their eyes, they will see frantic air traffic controllers squinting at their computer screens, unsure whether to direct their plane to Gatwick or de Gaulle, Cardiff or Kennedy.

It is the stuff of nightmares. Unfortunately, this nightmare is founded in reality.

A leaked report has revealed how air traffic controllers at Swanwick have misread the details on their computer screens. In one case, passengers on a flight to Glasgow were nearly redirected to Wales because the controller misread the code.

Controllers have also mistaken the heights of planes and sent them into the wrong air space.

Coming as it does before the double Jubilee Bank Holiday - set to be the busiest flying weekend of the year - this story will cause anxiety and anger.

Passengers have every right to be angry. A huge sum of money, £623 million, has been ploughed into the National Air Traffic Services (Nats) centre, and yet it has been plagued by problems. It came online five years late, by which time air traffic had increased beyond projections.

It was the subject of a hugely controversial part-privatisation, which led some opponents to dub Nats "the Railtrack of the skies".

In February a financial crisis precipitated by September 11 led to the taxpayer bailing it out with £30 million.

And Nats' expensive computer software has proved unreliable. Last Friday passengers faced cancellations and long delays after the computer network failed for the third time in four months.

It is disgraceful that a project as important and costly as Nats is still not as safe as it should be. This will further undermine public confidence in the air industry.

Along with Railtrack, Nats has proved the case for keeping Britain's transport infrastructure in State hands. Air traffic control should be in the public sector and funded through a tax on flights - a small price to pay for passenger safety.

Updated: 10:34 Thursday, May 23, 2002