Airbus SE will ask airlines operating 25 of its older A380 planes to inspect their wings for possible cracks, a problem that's arisen in the past on the double-decker aircraft.

Some fissures were found on planes in service, a condition that could reduce the wings' structural integrity if not corrected, the European Union Aviation Safety Agency said Friday.

The regulator is proposing an airworthiness directive related to the matter.

A wing-crack debacle seven years ago cost Airbus millions of euros in repair and service costs, only one of the issues that plagued the world's biggest passenger plane. Airbus said in February it would stop making the iconic double-decker.

The planemaker's shares fell 0.3% to 123.52 euros by 10:21 in Paris trading. The stock has advanced 47% so far this year.

Airlines must use ultrasonic testing methods for the inspections and if any cracks are detected alert Airbus for repair instructions before the plane's next planned flight, according to the EASA's directive.