CAA's general manager of general aviation, Steve Moore, said 15 New Zealand operators were approved to fly unmanned aircraft weighing more than 25kg.
It was the unknown number of smaller machines - the ones resembling multi-rotor mini helicopters - that caused most risk.
"The rules aren't fit for purpose - there's a lot of clever people coming out with commercial use of those aircraft and those rules just don't suit," Moore said.
There had been cases of drones being flown near airports, posing a hazard to planes taking off and landing. Farmers using them could also pose a risk, he said.
"If they fly it out of line of sight with no direct control over it, it could hit a topdressing plane - a remote possibility but it could happen."
The new rules would focus on the use of drones rather than their weight.
The "quick interim" steps would cover all operators who used them - mainly for photography and aerial surveillance.
They were not aimed at children flying toys.
"That's not a problem, they can continue to do that as they have for years, but a real estate company using [them] for photography in controlled airspace will need approval," Moore said.
Airways has just finished a project to ascertain the number of UAVs.
Airways general manager system operator Pauline Lamb said that in the past six months, 45 had been approved by control towers.
She said Airways aimed to allow the integration of the aircraft into normal operations rather than separating them.
The organisation had set up a website giving information and advice.
Heavy-handed legislation had been passed in Europe, but New Zealand authorities wanted to avoid that.
"From a safety perspective we'd like to be in a position where the industry self-regulates," she said.
Airways was used to complexities in its airspace and had previously integrated different types of aircraft such as balloons and gliders.
The organisation was doing research and development to build small and light transponders to help with surveillance of small UAVs.
One Wellington operator, Sycamore, uses drones for aerial photography for film and television but has slowed expansion.
"We, too, are concerned by the proliferation of the hobbyist users in New Zealand with little or no knowledge of the regulatory environment," said Sycamore's Ben Forman.
"We do not want to be tarred with the same brush as rogue drone operators, which could stifle our lead in a global industry worth an estimated US$11.6 billion annually and US$89 billion in the next 10 years."
Forman said mass market UAVs claimed to be fail safe but that was not the case.
"We see a lot of hobbyists flying with potential death traps in the sky."
Flying right
• Don't fly over 400ft.
• Don't fly at night.
• Don't fly within 4km of an airfield (approach paths).
• Don't operate in a way that may cause a hazard, eg, near people or property.
• Understand CAA model aircraft operating rules - go to the CAA website.
• Know your responsibilities as pilot-in-command of an aircraft.
• Fly within line of sight.
• Before you fly, check for airspace restrictions - controlled airspace, low-flying zones, danger areas, restricted areas and military operational areas.
