The number of people training to become pilots in New Zealand over the last decade has dropped.
Civil Aviation New Zealand's latest flight training safety report coincides with news that the global scarcity of pilots is forecast to worsen.
In 2009 there were 150 commercial aeroplane pilot licences issued.
That number has dropped to about 75 so far this year.
Nelson Pilot Training director David Marriott said two reasons stood out.
"It's really expensive to be a commercial pilot these days, and the other reason is that there's actually a lack of resources.
"Because there's such demand for airline pilots, all the instructors - who've historically not been well remunerated, have gone off to airlines and there's no one left to teach people."
Mr Marriott said it could cost between $120,000 and $150,000 to become a commercial pilot through training schools with NZQA approval and CAA certification.
It costs around half that to get a recognised qualification through an aero club or small flight school.
The CAA report said there had also been a steady decline over the past seven years in the number of both fixed wing and rotary (helicopter) private licences issued, with the most pronounced decline in commercial helicopter pilot licences, but there were now signs this was changing.
At the same time the rate of "airspace incidents" had increased significantly since 2007 but had begun to level off over the last year, the report said.
In the second quarter of this year there were 166 "safety occurrences" reported, involving mainly solo training flights.
They included students losing control of the aircraft on landing, losing their way in flight, and taking off without clearance.
Mr Marriott said the huge growth in demand for pilots, particularly in Asia, was going to have some interesting flow-on effects.
Air New Zealand said Boeing predicted the Asia-Pacific region would lead worldwide growth in demand for pilots over the next 20 years, which would see a requirement for around 250,000 new pilots.
Overseas airlines said another 500,000 pilots would be needed in other parts of the world in the next two decades.
An Air New Zealand spokesperson said the airline was working with its pilot union partners on a long-term strategy, and an industry Pilot Career Pathways working group was investigating ways to address the shortage.
Mr Marriott said it would likely mean the need for more training schools, but they were high-risk businesses.
"To have flying schools to cope with the demand, you have to go large - it has to be massive with a massive amount of resources, but the business risks are very high."
Mr Marriott said the security of the client base was very fluid, and never guaranteed.
He said the industry had done little in the past 20 years to foster talent, or encourage flying as a career.
"There's just been increases in charges and prices and more hoops to jump through."