John Key should fly Air New Zealand: New Zealand First

Prime Minister John Key should consider chartering an Air New Zealand flight or buying a seat instead of replacing the broken down New Zealand Air Force plane he uses for international travel, New Zealand First says.

The use of two 23-year-old Boeing 757-200s have again come under scrutiny from deputy leader Ron Mark after one broke down en route to India where Mr Key is set to hold a number of high level meetings, including with his counterpart Narendra Modi.

The Boeing was scheduled for only brief stopover in Australia but developed mechanical problems in Townsville meaning Mr Key and his delegation were forced to stay the night and wait for a replacement plane.

It has been slated for replacement, but Mr Mark said the Defence Force shouldn't have to foot the bill.

"If the Prime Minister wants 'PM 1' then his own department should fund the $140 million it will cost for something like an Airbus A320 instead of the New Zealand Defence Force," he said.

"Alternatively, we have an award-winning state airline that can do that job by charter or by buying a seat like the rest of us."

Mr Mark said the plane flew just 571 flight hours between January 2013 and September 2015, a fifth of what a commercial plane would do.

"It sounds counter-intuitive, but aircraft are much easier to maintain if they're kept flying than sitting on the tarmac," he said, highlighting his concerns about commercial jets flying too few hours in military service.

Meanwhile, Mr Key's curtailed visit to India will now centre solely on the capital New Delhi and pushing for progress on a free-trade deal.

It meant the planned trip to the financial capital Mumbai, meant to take up much of Tuesday, was ditched, and rest of the four-day schedule will be picked up in New Delhi from Wednesday.

That has meant the canning of a planned speech to the Bombay stock exchange, Asia's oldest, and an "innovation showcase" aimed at highlighting New Zealand technology companies and their Indian partners.

In New Delhi, Mr Key will meet his counterpart Narendra Modi, where he hopes to find favour with his business-friendly agenda.

The primary purpose of the Indian visit was to discuss move forward talks, which started with a hiss and a roar six years but have since slowed, Mr Key said.

India has protective tariffs for its agriculture but Mr Key wanted to see movement in meat and dairy product lines.

"I'm not coming to India with the expectation we'll get that resolved over the next few days, but I think over time we can push things along."

Mr Key said there would also be discussions about Indian students studying in New Zealand, where about 30,000 students a year were being taught but the number of fraudulent visa cases was skyrocketing.

Students were turning up without the correct paperwork or enough support and could be vulnerable, he said.

Meanwhile, Mr Key's stopover has landed him on the front page of the Townsville Bulletin newspaper on Tuesday morning.

Labelling him the "accidental tourist", the paper grabbed New Zealand's tourism minister while he went out for a drink and a meal and quizzed him on the possibility of direct flights between the city and Auckland.

Local business leaders are keen on such flights and were hoping Mr Key's visit could be a catalyst, the paper reported.

"I think it's a great idea if they can get it to happen," he said. "It's really impressive, a lovely place."

It's not the first time in recent months the PM has had plane trouble.

One of the 757s was grounded for several hours in Laos last month after Mr Key attended the East Asia Summit.

The plane was flown to Guam for repairs while Mr Key attended the Pacific Islands Forum before returning to New Zealand.

-With NZN