EASA is taking precautionary measures to prevent any further similar occurrence.
Hong Kong-based Cathay, one of the largest operators of the A350 jetliner, grounded 48 planes for checks on Monday after a Zurich-bound flight had to return to the city shortly after take-off.
Initial investigations have revealed that a flexible pipe feeding a fuel injection nozzle in the XWB-97 engine was pierced, the sources said.
Inspections found defective engine fuel lines requiring replacement on 15 of the A350s powered by Rolls-Royce engines, forcing the cancellation of dozens of flights in Asia.
The agency said the incident was the subject of a safety investigation led by the Air Accident Investigation Authority of Hong Kong (AAIA) and added it is taking “precautionary measures to prevent any further similar occurrence.
EASA said the inspections would seek to “identify and remove from service any potentially compromised high pressure fuel hoses” and said the compliance time frame was still being determined and would be detailed later Thursday in an EASA Emergency Airworthiness Directive.
