Hong Kong flag carrier Cathay Pacific Airways has completed repairs on its Airbus A350 aircraft after 90 flights were cancelled in the past week following an engine fire that led to the discovery of a "first-of-its-kind problem" involving fuel hoses.
The large-scale cancellations allowed the airline to carry out inspections and repairs of its 48-strong fleet of A350 aircraft, with the European aviation regulator also ordering carriers using some models of the widebody jets to conduct their own checks within a month.
Cathay Pacific said on Saturday it had finished its work on its A350 fleet.
"Cathay Pacific advises that maintenance activity on its operational Airbus A350 fleet has been completed," the carrier said. "All A350 aircraft that require replacement have gone through successful repairs and cleared for operation."
The airline announced on Monday it had grounded the planes after discovering the problem with a part in their engines, which are manufactured by Rolls-Royce.
Engineers identified the failure after Zurich-bound flight CX383 returned to Hong Kong following take-off early on Sept 2. Confirming a report by the South China Morning Post, the European Union Aviation Safety Agency later said the flight suffered a "serious" engine fire.
A source told the South China Morning Post earlier that deformed fuel pipes used to transfer fuel were the reason behind the failure of the engine part, while adding the carrier was under "no mandate" from the manufacturer or any regulator to inspect or replace the pipes.
Cathay said on Wednesday that it had identified 15 aircraft out of its 48-strong A350 fleet that had engine fuel lines requiring replacement, with six of the aircraft already repaired and cleared to operate.
It had expected the remaining nine to be repaired and ready for operation by Saturday.
The engine problem also prompted other airlines with the same model of plane to conduct inspections, including the Singapore Airlines and Japan Airlines.
Just days after Cathay made the call to ground the A350s, the European agency said it was taking precautionary measures to prevent any similar occurrences.
"We will require a one-time fleet inspection, which may be applicable only to a portion of the A350 fleet, in order to identify and remove from service any potentially compromised high-pressure fuel hoses," it said.
The regulator later issued an emergency airworthiness directive for a phased inspection of flexible fuel hose connections inside Rolls-Royce Trent XWB-97 engines that power A350-1000 aircraft. The inspections should be carried out in the next three to 30 days, depending on the history of each individual engine, the agency said.
There are 86 A350-1000 aircraft in service worldwide.
According to flight data provider Cirium, Qatar Airways operates a fleet of 24 A350-1000 passenger planes, followed by Cathay with 18 and British Airways with 17.
"This action is a precautionary measure, based on the information received from the initial investigation of the recent Cathay Pacific serious incident and on the airline's findings in its own subsequent inspections," said Florian Guillermet, executive director of the European body.
"We will continue to follow closely all information that will be made available through the ongoing safety investigation."
Hong Kong's Civil Aviation Department said on Friday the agency's directive was applicable to all airlines using A350-1000 aircraft following an online meeting with the regulator about the direction of the investigation on Wednesday.
Cathay had already conducted a thorough inspection of its fleet and so had complied with the directive, it added.
"The [department] attaches great importance to aviation safety, seeking to ensure all the A350 planes passing through Hong Kong comply with the directive," it said.
"We will continue to follow up the investigation and keep close contacts with the European Union Aviation Safety Agency, and the engine manufacturer for further action to ensure aviation safety."