Travel agents are expecting to be flooded with calls after Air New Zealand cancelled flights over the holiday period affecting 14,000 people because of maintenance issues with its Rolls-Royce engines.

Photo: Supplied / Air NZ

The national carrier has been forced to suspended its twice-weekly Christchurch to Perth service and cancel dozens of other international flights in December and January, mainly between Auckland and Sydney and Auckland and Perth.

Ongoing problems with some Rolls-Royce engines on the Boeing 787-9 aircraft mean they need frequent maintenance which has caused a significant backlog at Rolls-Royce's international plant.

Air New Zealand said it thought the issues would be cleared by Christmas but it is still in the queue at the Rolls-Royce repair shop.

Brent Thomas from House of Travel said it would have a huge impact on a large number of customers.

"It is an a unfortunate period, particularly over the Christmas period when so many people are travelling.

"This is going to be significant, just the number of people who are potentially impacted."

He said travellers should immediately contact their travel agent or risk missing out.

The engine problems were bedevilling airlines worldwide, he said.

"We have to stress this is because of the Rolls-Royce engines. And it's not just Air New Zealand who are impacted, there's going to be significant number of airlines around the world, and we'll be dealing with those airlines as well."

Aviation commentator Irene King said the Christmas cancellations would hurt Air New Zealand's brand.

She said while the airline could have been better at making contingency plans it was at the mercy of the backlog at the international Rolls-Royce maintenance plant.

But she said passengers would forgive the hassle of rebooking if it meant they would get to their destination safely.

"It comes down to 'how annoyed are you because this cancellation is caused by the need to ensure absolute reliability and safety with engines'."

Air New Zealand has warned there could be further cancellations as it progresses with the engine checks.