There have been 21 accidents for external load operations from 2000 to 2019, the CAA says.
Aviation bosses have met for crunch safety talks after a series of high-profile helicopter crashes.
The New Zealand Air Line Pilots' Association (ALPA) sat down with Civil Aviation Authority (CAA) boss Graeme Harris in a top-level meeting facilitated by Transport Minister Phil Twyford in the Beehive last month.
It comes after a tough few months for the CAA where it has been accused of failing in its industry watchdog role, and of operating a "toxic" work environment.
Documents released under the Official Information Act show 20 formal complaints by CAA staff about bullying, sexual harassment or inappropriate behaviour in the last four years.
And in May, it was criticised by the Transport Accident Investigation Commission (TAIC) for poor oversight of a Fox Glacier helicopter operator before one of its choppers crashed in 2015 and killed pilot Mitch Gameren and six tourists.
While the CAA says there has been a "significant decrease" in the number of helicopter accidents in New Zealand over the past four years, "we still have a lot more work to do to improve safety in the helicopter sector, especially when it comes to underslung loads", Harris admitted in a newly-released CAA briefing document.
"It was with this in mind that I met with incoming ALPA president Andrew Ridling and Transport Minister Phil Twyford [last] month," he said.
The issue of underslung loads, which includes firefighting choppers flying with monsoon buckets attached below, arose in a wide-ranging discussion of safety issues that need to be looked at across the industry, the Herald understands.
Ex-SAS war hero Steve Askin died while using a monsoon bucket to fight the 2017 Port Hills blaze.
Askin was flying a Eurocopter AS350 "Squirrel" helicopter – the same machine that industry legend Bill Reid was operating when he survived a hard-landing fighting the Pigeon Valley bush fire in February.
Today, Harris said that accidents involving underslung loads "represent a high proportion" of total helicopter accidents in New Zealand.
There have been 21 accidents for external load operations from 2000 to 2019, which represents six per cent of total helicopter accidents during that period.
"Any type of operation where there is a history of serious or fatal accidents, or there is recognised high potential for an accident, is a concern. Underslung load operations fall into this category. This is something that will be addressed as we continue to work with industry," Harris said.
New ALPA president Ridling was joined by immediate past president Tim Robinson and ALPA general manager Dawn Handforth at the meeting. Twyford was in the room along with a handful of ministerial staff.
At the meeting, the CAA and ALPA agreed to work closer together on improving safety performance in the non-passenger helicopter sector, the Herald understands.
"Improving safety outcomes for this sector is vitally important and we welcome the opportunity to work with anyone who shares the common interest of preventing the needless death and injury that is currently being seen in the industry," Harris said.
Twyford welcomed ALPA's "constructive offer" to work together with the CAA and bring its expertise to help with some of the big industry challenges.
"Public agencies like the CAA must always be open to constructive criticism and constantly looking to improve their performance," the minister said today.
"Our Government takes safety very seriously, and the Ministry of Transport is continually reporting to me on the CAA's regulatory performance."
ALPA offered access to the knowledge and expertise of its 2000-plus strong membership, with Ridling wanting a more "collaborative approach" to aviation safety in New Zealand.
Airline pilots, air traffic controllers, plane manufacturers, engineers, and the CAA should all be working together," Ridling told the Herald.
"The industry is moving at such a rate, in technology and change, that CAA just can't keep up – nobody in the industry can keep up by themselves," he said.
"We have the same objectives [as CAA] and it's about safety. I know the CAA is there for the safety of the public, and ours is towards the safety of our members, but if I get home, then everybody on board the aeroplane also gets home."