New Zealand's airports are woefully under prepared for the numbers of tourists coming through their gates, an aviation commentator says.

New Zealand airports are under prepared for the amount of tourists coming through the gates. Source: rnz.co.nz

In an email sent to customers, Air New Zealand chief executive Christopher Luxon said he was frustrated with the under investment by local airport companies that has created backlogs for travellers.

Mr Luxon also announced that Air New Zealand will stop flying to Vietnam from next year due to engine maintenance issues involving Rolls Royce powered planes.

Aviation commentator Peter Clark said Air New Zealand's problems have been ongoing for years.

"Auckland Airport is a classic example, it's been trying to play catch up for years and it's too late, it should have been done," Mr Clark said.

"The government needs to look into this, where have we gone so badly wrong in New Zealand?"

Mr Clark said he was also concerned New Zealand businesses have not learnt enough lessons from last year's Marsden Point pipeline shut down.

The 10-day shut down last September was caused when a digger burst the pipeline near Ruakaka, spilling up to 80,000 litres of fuel on nearby farmland and causing severe disruption to flights.

Mr Clark said if another burst were to occur, it would be catastrophic.

"If we have a problem and a plane is stuck on a runway for even more than half a day it causes absolute chaos in New Zealand by diverting aircraft, putting people up, accommodation, getting crews to fly aircraft's. Where is the total back up?"

In a statement, a spokesperson for Auckland Airport said it was planning to invest around $2 billion in its business over the next few years as part of a 30 year plan to develop the facility.

He said that included plans for a second runway, new car parking options, improvements to the Domestic Terminal, and new food and beverage outlets.