Investigators probing an engine explosion on an Air France A380 in 2017 are studying a possible manufacturing flaw after a part of the aircraft that had fallen off was found to have cracks in it.
Reuters reports the discovery will likely trigger urgent checks on dozens of Airbus superjumbos, according to people "familiar with the matter".
The focus of a two-year-old investigation into the mid-air explosion over Greenland - which left the plane carrying more than 500 passengers with the front of one engine missing - has switched to the "fan hub", which was recently located on the ground in Greenland.
The titanium alloy part is the centerpiece of a 3m wide fan on engines built for the world’s largest airliner.
It had sat buried in Greenland’s ice sheet since September 2017, when one of four engines on Air France flight 66 abruptly disintegrated en route from Paris to Los Angeles. It was pulled from the ice in June after an aerial radar search.
France’s BEA air accident agency said it had discovered a "sub-surface fatigue crack" on the recovered part and the engine maker was preparing checks.
The people familiar who spoke to Reuters on the condition of anonymity, linked the crack to a suspected manufacturing flaw and said the checks - to be carried out urgently on engines that have conducted a certain number of flights - would affect dozens of the double-decker jets.
The sources said the suspect part was fabricated on behalf of consortium member Pratt & Whitney, which declined to comment.
Engine Alliance engines power a total of 152 aircraft or just over 60 percent of the 237 A380s in service.
In the video above, parts of the engine can be seen hanging off the aircraft as its pilot declares mayday.
Besides Air France, other airlines operating the A380 with Engine Alliance engines include Emirates, Qatar Airways, Etihad and Korean Air.
The checks will involve taking planes out of service outside their usual maintenance schedules, one source said.
Taking an aircraft out of operation can cause major headaches for airlines.
Investigations are not complete and are likely to tackle other features such as the loads or physical forces at play. Experts say air accidents are rarely caused by isolated factors.
Airbus declined to comment.