The breakdown of Prime Minister John Key's military plane in Australia is the latest in a series of Air Force incidents and has given further ammunition to those who say the ageing fleet should be replaced more quickly.

It has also caused some Opposition MPs to return to the issue of whether the Prime Minister should be using Royal New Zealand Air Force planes for international travel.

A New Zealand delegation headed for India was stuck in Townsville overnight after the Air Force's Boeing 757 broke down. The delegation is now en route to New Delhi after they were picked up by the Air Force's second 757.

Labour's defence spokesman David Shearer said the latest breakdown was embarrassing for New Zealand, especially as it meant a day was lost on the business trip to India.


"While we know the Air Force does its best, it's pretty clear that some of the equipment that it's using is not up to the task.

"Given the Air Force planes can only fly three or four hours before they have to stop for a refuel, it means a very long trip to somewhere like India or the Middle East."

The Defence White Paper released in June said the 757s would be replaced, but not until the early 2020s.

"In light of what happened today, the Air Force might need to be looking at what needs to happen to these planes so we don't have continual breakdowns," Shearer said.

New Zealand First defence spokesman Ron Mark said the problems in Townsville raised questions about the benefits of the Defence Force using its aircraft to transport the Prime Minister.

Mark said Key should instead purchase an aircraft like the Airbus 320, at a cost of $140m, instead of relying on the 757s.

He said commercial planes were easier to maintain if they were used regularly.

"Between January 2013 and September 2015, our 23-year-old Boeing 757's flew only about 571 flight hours each year.

"That's only about a fifth of what a 757 flies in commercial service."

The breakdown of the Boeing 757 follows a spate of recent problems with various Air Force aircraft.

Last month, emergency services were called to Whenuapai Air Force base after the crew on a P3K2 Orion noticed an electrical fault while taxiing.

On August 18, a C-130 Hercules with 30 passengers made an emergency landing at Whenuapai after its engine overheated mid-flight.

Three days earlier, one of the Boeing 757s had to make an emergency landing at the same airport because of a punctured tyre that caused vibrations during its take-off.

And on June 29, the crew on a Hercules declared an emergency after reporting pressurisation issues, which forced them to land the plane.

The Air Force's two Boeing 757s were bought by the Labour-led Government in 2003 for $221m.

They had been in service for 10 years as commercial airliners.

The 757 model usually depreciates within 15 to 20 years, but can be flown safely for longer if well maintained.

The Air Force's 757s were upgraded in 2008-09 at Mobile Aerospace Engineering in Alabama, where their floors were strengthened and they were given a new cargo handling system and new communications and navigations systems.