Airport hit by road worries

Sydney airport's new baggage handling system crashed again on Sunday less than a month before tens of thousands of extra passengers arrive for the Olympic Games.

Planes were delayed and luggage was lost as a result of the second breakdown in three days.

It was the sixth incident altogether since the $25.8 million computerised system was installed three months ago.

There have also been air traffic control problems and security scares at the airport in the past two months.

In the latest trouble, 20 flights were delayed for four hours and about 20 bags did not reach their owners' flights, a Sydney Airport statement said.

"Sydney Airports Corporation has now identified the fault as a computer database problem associated with the implementation of the new baggage security system which is required for the Olympic Games," the statement said.

The airport is also struggling with power supply problems to its air traffic control system with two malfunctions causing serious flight delays in the past month.

Airservices Australia, responsible for air traffic, was forced to shut eight of its 12 air traffic control positions after losing main and back-up power for about 90 minutes three weeks ago.

In early July, 20 aircraft had to circle without contact with air traffic controllers for up to 15 minutes after a blackout knocked out main and back-up power.

The government has also ordered an inquiry into security at the airport after two intruder scares in the past month.

A mentally disturbed man was found asleep in the cockpit of an Air New Zealand jet and another man was detained after a Qantas crew saw him waving at an arriving jet from the tarmac.

Both men were believed to have climbed over fences and walked across the tarmac undetected.

The statement on the latest baggage handling mishap promised the faults would be solved by the time the Olympics start on September 15.

Australian media have demanded urgent action to solve the airport problems, claiming they seriously threaten Australia's reputation as a tourist destination.