Passengers at Dublin Airport can expect ongoing delays for several weeks as engineers continue to work around a computer system glitch responsible for causing last week's radar system meltdown, the Irish Aviation Authority revealed.

Delays during non-peak times should average about 20 minutes, according to IAA spokeswoman Lilian Cassin.

However, longer delays of varying lengths can be expected during peak flying times -- including the morning rush-hour between 6.30-8.30am, lunchtime, teatime and late evening -- although they are not expected to be excessive, she added.

"We're getting the majority of aircraft anyway within 15 minutes [of scheduled arrival or departure]," she said.

The cause of the radar system crash, which caused chaos for airlines and passengers alike last week, has been blamed on just one intermittently-malfunctioning computer component.

The faulty network card overwhelmed the €100m radar system designed by the French- based company Thales ATM, regarded as the world's leading air traffic control systems provider.

Computer data showing the location, height and speed of approaching planes disappeared from screens for 10 minutes each time.

The glitch appears to be unique to Dublin Airport for reasons the company has been unable to ascertain.

"Thales ATM stated that in 10 similar air traffic control centres worldwide with over 500,000 flight hours, this is the first time an incident of this type has been reported," according to the IAA.

"They're describing it as a unique failure. They've never seen it before."

However, the glitch in the network card -- which normally allows computers to communicate with each other -- has been cited as the reason for ongoing problems with the Dublin Air Traffic Control Centre radar system over the past five weeks.

The problems, dating back to June 2, reached a crisis point on Wednesday last, forcing engineers to effectively shut down the system in order to determine the cause of the problem.

The system malfunction lead to travel chaos for tens of thousands of passengers who were delayed or left stranded for hours, if not days last week.

Severe disruption continued for several days afterwards and the system is still not yet back to normal and is currently operating at only about 80pc capacity, according to the IAA.

However, the IAA is hopeful that the ongoing delays will get progressively shorter as engineers gain more experience working around the problem, Ms Cassin said.