The six Qantas superjumbo jets are part of a global fleet of 25 affected aircraft the European Aviation Safety Agency said will need inspecting.

The other airlines requiring inspections include Emirates, Singapore Airlines, Air France and Lufthansa.

Qantas Head of Engineering Chris Snook said Qantas was taking the issue very seriously and acting proactively.

“Inspections are not required on these aircraft for another year or two and are being done well in advance of the required time frames,” Mr Snook said.

“We have completed inspections on two aircraft and there were no concerns with the structural integrity of the wing.”

Airbus said in a statement that the cracks were found on the outer rear wing spars.

“We have identified the issue and designed an inspection and repair scheme,” the company said.

“The inspections and repairs can be accomplished over scheduled heavy maintenance checks.”

The European Aviation Safety Agency said the cracks, if not detected and corrected, could reduce the structural integrity of the wing.

Emirates, the world’s largest A380 operator, has started checks on nine of its superjumbos and “so far, there has been nothing untoward in the findings”, a spokeswoman said.

With AAP