Cathay Pacific says another 22 flights will be cancelled from September 5-7 as work continues to replace fuel lines on numerous A350 planes.

Engineers identified 15 aircraft in need of repairs after a flight to Zurich was forced to return to the SAR due to a glitch on Monday.

The airline said a total of 90 flights have been cancelled this week, but some of the planes affected have already been repaired and all 15 are expected to be back in service by Saturday.

"Completing thorough inspection and maintenance for all A350 aircraft within such a short timeframe has been challenging. The ability to safely deal with and resolve this issue reflects the can-do spirit of Cathay’s people. I would like to express my sincere thanks to our engineering and frontline teams, along with our partners, for their support and commitment to resolve the situation and minimise flight disruptions," said Chief Operations and Service Delivery Officer Alex McGowan.

"I would also like to extend my apology to customers whose travel plans were affected by this incident. At Cathay, the safety of our customers and our people guides every decision we make."

The airline said the engine component failure identified in its planes is the first of its kind on any A350 anywhere in the world.