(Reuters) - A probe by Hong Kong's aviation authority found a ruptured fuel hose caused a mid-flight fire on a Cathay Pacific operated Airbus A350 plane this month.
The aircraft was en-route to Zurich with 348 passengers and crew aboard when the fire was discovered, forcing it to turn back to Hong Kong, where it landed safely. The incident resulted in the grounding of a number of other Cathay flights.
Hong Kong's Air Accident Investigation Authority (AAIA) said on Thursday its investigation had found the ruptured fuel hose in the jet's second engine, with five secondary hoses also showing signs of wear and tear.
"This serious incident illustrates the potential for fuel leaks through the ruptured secondary fuel manifold hose, which could result in engine fires," the AAIA said in a report.
The AAIA also told engine manufacturer Rolls-Royce (OTC:RYCEY) to impose certain inspection requirements for such components.
Rolls-Royce did not reply to a request for comment. Airbus did not immediately respond to a request for comment.
The AAIA probe confirms a Reuters report which cited sources saying initial checks revealed a hose between a manifold and a fuel injection nozzle was pierced.
"If not promptly detected and addressed, this situation, along with further failures, could escalate into a more serious engine fire, potentially causing extensive damage to the aircraft," the AAIA report said.
Cathay said it had contacted the manufacturers of the aircraft and the engine as well as the regulator after the fire.
"As a precautionary measure, it proactively initiated a fleet-wide inspection of its Airbus A350 aircraft that cleared the aircraft for operation," the Hong Kong flag carrier said in a statement emailed to Reuters.
Cathay began inspecting all its Airbus A350 jets after the incident, saying it was the first component of its type to suffer such a failure on any A350 aircraft worldwide.
The European Union Aviation Safety Agency (EASA) also ordered inspections on Airbus A350-1000 engines in a move to prevent similar events after consulting regulators and accident investigators in Hong Kong, as well as Airbus and Rolls-Royce.
The AAIA, in its report, recommended the EASA ask Rolls-Royce to continue giving airworthiness information, including inspection requirements of the secondary fuel manifold hoses of its engines to ensure their serviceability.