European air safety officials are preparing to extend checks for Airbus A380 wing cracks to the entire superjumbo fleet, sources close to the matter told Reuters on Wednesday.

The move to inspect all 68 A380s in service came as Qantas Airways grounded one of its planes, saying engineers had found 36 wing cracks after the aircraft encountered severe turbulence.

By signaling that the defects may be structural and widespread, the fleet-wide inspection order will refocus attention on flaws identified in flagship jets at both Airbus and Boeing . The aircraft makers maintain that their newest jets remain safe to fly after problems were caught at an early stage.

This is an extension of a process already underway, said one of the people, who asked not to be named. An effective repair has been identified.

Airbus, a unit of European Aeronautic Defence & Space Co. , declined to comment on the additional inspections. A spokesman for the European Aviation Safety Agency (EASA) was not immediately available.

The aviation watchdog last month ordered checks on one-third of the A380 fleet after cracks were found in a handful of the thousands of L-shaped brackets that fix each wing's exterior to its internal ribcage-like structure.

EASA has yet to set out a timetable for the new inspections, two aviation sources said. Planes will be checked as they cross wear-and-tear thresholds at which the tiny cracks become detectable.

Inspectors had initially focused on 20 aircraft operated by Singapore Airlines , Air France and Dubai's Emirates - which have logged the most A380 flights since the double-decker plane entered service four years ago.

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(Reporting by Tim Hepher; writing by Laurence Frost; Editing by Geert De Clercq and Jane Merriman)