Hong Kong aviation investigators say an engine problem that caused Cathay Pacific to ground its entire fleet of Airbus A350 jets for inspection earlier this month could have escalated into “extensive damage.

The preliminary investigation into an incident involving Cathay Pacific Airways (OTCPK:CPCAY) operated Airbus (OTCPK:EADSF) A350 revealed a rupture in the fuel hose, said Hong Kong's aviation investigation authority on Thursday.

Hong Kong's air safety authority said Thursday that a defect in an engine component of a Cathay Pacific Airways Airbus A350 that caused a fire, forcing a Zurich-bound flight to return to Hong Kong, could have caused ''extensive damage'' to the aircraft.