Qantas will inspect its fleet of Airbus A380s for cracks on its wings following a European directive, but the engineers' union says it should have happened months ago.

The airline will check all 12 of its superjumbo jets for structural damage on parts inside the wings following directions from the European Aviation Safety Agency (EASA).

The agency last month issued an airworthiness directive calling for "a detailed visual inspection" of the 20 planes that have flown the most, but that has now been extended to the entire fleet of 68.

A Qantas spokeswoman said the airline would "comply fully with the (EASA) directives" and begin inspections in the next few weeks.

But Australian Licensed Aircraft Engineers' Association (ALAEA) federal secretary Steve Purvinas said that while the inspections were necessary, they should have been made sooner.

Mr Purvinas said cracks were first discovered in the so-called "wing rib feet" -- the metal brackets that connect the wing's ribs to its skin -- in several A380s in the global fleet months ago.

"We've been calling for these checks to take place for two months now," Mr Purvinas said.

"It shouldn't have taken them two months to work out that these cracks are only going to get bigger, and the inspection should have been mandatory as it's now been made."

Senior aviation school lecturer at the University of NSW, Peter Marosszeky, said the checks were not cause for alarm, because the aircraft had only been flying internationally since 2007 and some were likely to have minor "teething problems".

Mr Marosszeky, also a former Qantas engineer, said the ordered checks on the aircraft were "an eminently sensible idea".

He said cracks such as those discovered so far posed "no threat to safety", and that routine checks meant it was "very unlikely" such cracks could worsen to the point of becoming dangerous.

However Mr Purvinas said the cracks were only first discovered by engineers carrying out repairs, and had not been picked up during routine checks.

Qantas grounded one of its A380s on Sunday after 36 hairline cracks were discovered on its wings.

The plane was hit by severe turbulence last month on a flight from London to Singapore and seven people were injured.

Qantas said those cracks were "not related to the turbulence, or specific to Qantas", but had been traced back to a manufacturing issue, and had no effect on flight safety.

It also said the type of cracking was different to cracking found on certain A380s in the global fleet.