National Party leader Christopher Luxon says if he becomes Prime Minister he won’t be using the “ancient” breakdown-prone Defence Force planes that are “well past their use-by date” for overseas travel and will instead use commercial and charter options.

Luxon says he won’t bring forward the current replacement schedule for the 30-year-old planes of 2028 to 2030, saying it should not be a priority in an economic recession.

It comes after Luxon called the fact Prime Minister Chris Hipkins had to have a backup plane on hand for his trip to China this week in case the main aircraft broke down “embarrassing” and caused unnecessary carbon emissions.

The secondary plane was pre-positioned in Manila, Philippines, while the 81-strong delegation travelled from New Zealand to China on Sunday. The second plane is now stationed in Darwin, Australia, and prepared to assist if needed.

The two Boeing 757 Air Force passenger aircraft were purchased second-hand in 2003 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.

Former Prime Minister Jacinda Ardern had to contend with a series of breakdowns in her time - which also occurred during former Prime Minister John Key’s tenure - raising questions about bringing forward the current replacements schedule, set to occur between 2028 and 2030.

Luxon said he would not use the planes if he was elected Prime Minister and would not bring forward the replacement date due to the current economic climate. He would instead fly commercial.

“It’s very obvious that they are unreliable, in spite of the great work of Air Force personnel who managed to keep them working and well maintained and safe.

“But the second thing is... We are in a recession that this government created and it’d be inappropriate for us to actually commit and spend money on new planes in a recession. And therefore my personal view is you travel commercial.”

Asked how practical this would be with 81 people in a country like China, with a schedule shifting across the country, Luxon said there was a “whole range of options”, including charter planes.

“These are ancient aircraft, they shouldn’t be flying that well past their use-by date.

“We are now in a recession, and this will not be a priority in my government. And so the reality is whether you like it or not, we travel commercial, we charter aircraft, we do a whole bunch of other arrangements that are possible.”

Asked about the extra expenses of flying commercial and charter, especially given these planes will continue to be used by the Defence Force anyway for a range of operation and need to be flown often to stay in good condition, Luxon said over $100 million dollars had been spent in recent years on maintenance alone.

The Act Party obtained information showing $70 million was spent on maintenance and repairs between 2017 and mid-2022. Less than a year since then and a further $33m has been spent.

A spokesman for the Prime Minister said on Monday the two planes had not travelled to China. The backup aircraft went to Manila, Philippines, and would now proceed to Darwin, Australia, where it would be based to provide support on the return journey from China if required.

“Backup was put in place in the event that the flight broke down on the way up, but it is not shadowing the plane around China,” he said.

The spokesman referenced similar situations under former National Prime Minister John Key when a “highly-publicised series of breakdowns” affected a delegation he led to India in 2016.

Rules were then updated to provide for backup aircraft based on the circumstances of a trip, and it is not unusual that in some instances backup aircraft are provided, the spokesman said.

“Whether the [Air Force] provides backup aircraft is an operational decision based on a combination of factors, such as the importance of the mission, the distance being flown.

“With this particular mission, with a delegation going a long distance, and with the Prime Minister and around 45 others delegation members board on board (plus air crew, plus media), it was considered that backup aircraft were justified to ensure the success of the mission to what is New Zealand’s largest trade partner.”

Using Air Force planes was cheaper than a commercial charter and had other benefits such as security assurance, and the ability to travel point to point to reduce time away from home and additional costs such as hotels which would be required if there were stopovers, he said.

After Key’s breakdowns in 2016, it was reported the planes would be replaced in the early 2020s.

The Herald has sought a response from the PM’s office and the Defence Force about why that replacement date has been pushed out to 2028.