Australian air safety investigators say they have identified a potential manufacturing fault in some jet engines fitted to the world's biggest passenger plane, the Airbus – A380. They said there was a critical safety issue that could in some cases lead to catastrophic engine failure. Experts say the problem which is thought to have caused the mid-air disintegration of an engine on a Qantas super jumbo last month has been traced to an oil tube connection in the Trent 900 engine.