Kiwi aerospace entrepreneurs are pushing ahead with air taxis for the Brisbane Olympics, reusable rockets, and tree-spotting drones, despite frustrations with red tape.

The rising volume of innovative aircraft in the fledgling industry is testing the limits of the country's regulatory system.

Simon Conroy, a director of Aerolab in Auckland, has just returned from marketing spray drones at the Fieldays in Waikato.

"We probably spoke to two dozen farmers or sprayer operators out there who were keen to purchase there and then," he said.

"But the fact that they would buy the machine and then have about 12 months of it sitting in the garage collecting dust before they could operate it, was a massive hurdle for them."

He has been bringing in the drones for about a year but is still waiting on the Civil Aviation Authority (CAA) to approve them because they weigh over 25kg.

Each operator also needs what is called a Part 102 certification.

"There was an incredible amount of demand and interest out there," Conroy said, "but the common theme with all the people we spoke to was the fact that a year to 18 months to get certified is going to be a real handbrake on people's ability to adapt and get these things out there in the field."

The delays were at the heart of addressing their monthly cash burn as a start-up, he said.

They had a buffer from sales of land-based robots and were carrying on with government-funded tests of small drones that can tell how much carbon is in a forest, for climate change calculations.

"We're not saying we want to jump the queue, just engage with [the CAA] and a dialogue," Conroy said.

Industry group Aerospace New Zealand can, at the drop of a hat, name 17 companies - local or foreign-owned - that are pushing on with innovative projects (see below).

One of them is Melbourne's Swoop Aero, which is seeking CAA approval to carry pathology samples by 120km/h drone on the West Coast.

That will extend to carrying supplies in a Civil Defence emergency, and perhaps a national rollout, a spokesperson for Te Whatu Ora Health NZ said.

"Having access to this technology during... emergencies will enable our teams to continue providing these services with minimal disruption."

Swoop is calling it "New Zealand's first integrated drone logistics network".

But Aerospace NZ also warns next year looks like being make-or-break for some players unless there is a regulatory breakthrough.

CAA has said it is adding staff and resources and streamlining safety certification processes.

Unlike many others, Catherine MacGowan of Wisk Aero does not have a bad word to say about the regulator.

"There are a lot of positive building blocks here."

Part of her optimism is undoubted because of the progress Wisk is enjoying in Australia getting its vertical takeoff autonomous air taxis lined up to launch at the 2032 Brisbane Olympics.

"The Olympics provide a really good rallying point around introducing this new type of technology, but we're also working closely with the regulators in Australia, in the same way as we are in New Zealand."

Wisk has also done a deal with Queensland mayors to collaborate.

Wisk has shifted its air taxi testing from New Zealand to its home base of California but stresses that was not because of any barriers. It remains part of a programme of fledgling trials here, into how newfangled craft will be used. The government just put $3m into that.

Local start-up Dawn Aerospace is part of the programme too, but notes "there hasn't been a whole lot of action under that just yet".

Dawn has 33 satellite thrusters in use and 200 more in production and is about to put a rocket engine for the first time on its reusable spaceplane. It has doubled revenues and in size in a year, to 100 employees, said chief executive Stefan Powell.

"Our programme, our capability is accelerating," Powell said.

"CAA has been pretty forthcoming and good to work with - in saying that, there's just not enough work being done. You know, we just need to have them sort of scale up with us."

At Aerolab, Conroy said they had an idea to help cut the queue - that their clients could "share" their 102 certifications until they got their own - but could not even get it in front of CAA.

"There's only a handful of people who are qualified to certify in there. Plus we also suspect that there's some issues around, kind of, embracing technology."

CAA has just added two more certifying inspectors to its team of four.

Conroy is signing all his clients up to OneReg, an Auckland start-up digitising the regulatory process.

"We believe that coming from the corporate world, not the aviation or agricultural world, that digitisation is one of the ways we can introduce a bit more efficiency."

OneReg's founder Clinton Cardozo said the boom in aerospace innovation had caught regulators flatfooted in lots of places.

"Obviously there are other countries that are a lot better resourced, you know, the government only has that much money," Cardozo said.

"But it's not like the problems go away moving to another country. The other regulators are speaking to us, so clearly they wouldn't be speaking to us if the problem didn't exist over there as well."

Aerospace innovators in NZ - a rough guide

• Dawn Aerospace - satellite thrusters and reusable rocketplanes
• Merlin Labs, Skybase - autonomous flight for existing planes
• Argo Navis Aerospace - rocket propulsion
• Kea Aerospace - solar-powered stratospheric aircraft
• Fabrum - cryocoolers and green hydrogen
• Asteria, Ruamoko Innovation, Contour Engineering - aerospace engineering
• Electric Air - electric planes
• Swoop Aero - delivery drones
• Pyper Vision - airport fog dispersal
• Wisk - air taxis
• Aerosearch - remotely piloted aircraft
• Syos Aerospace - heavy-lift drones
• Awarua Tracking Station - European Space Agency etc satellite/rocket tracking
• Tāwhaki - R&D test site at Kaitorete