THE discovery of tiny cracks in one of the wings of a Qantas A380 under extensive repair in Singapore has led to the detection of similar problems in four other Airbus superjumbos worldwide.

The cracks - less than a centimetre long - in the wing ribs of the A380s do not pose an immediate threat to the safety of the aircraft. The ribs are vertical fixtures that stabilise the wings.

Winged ... an A380, damaged in 2010, is being repaired in Singapore. Credit:Reuters

But their detection is expected to prompt Airbus to issue a service bulletin to airlines later this month requiring them to check for the problem when their A380s are due for heavy maintenance every four years.

Engineers only discovered the cracks in the wing ribs of the Qantas A380 - named the Nancy Bird-Walton - while they were conducting $130 million in repair work on the aircraft at Changi Airport.