Regional airline Sunair says it has been grounded.

However, its chief executive said people who’d already booked trips could still travel, as flights with other operators had been arranged.

The Tauranga-based airline said it was not allowed to fly after a 10-day ban started late on Wednesday.

“About three weeks ago we had a maintenance audit and there were some issues identified,” chief executive Doug Roberts told the Herald.

He said the Civil Aviation Authority (CAA) had some issues with record-keeping.

He said the relevant details were basically deemed not to have been recorded the way the authority wanted.

The airline’s certificate of airworthiness was revoked.

“Effectively in layman’s terms, it’s the WoF [Warrant of Fitness],” Roberts said.

Sunair operated five Piper PA-23 Aztec and three Cessna 172 aircraft.

The Aztec is a twin-engine, six-seater and the 172 is a single-engine, four-seater.

Roberts said the CAA advised Sunair to have “more robustness and rigour” with the relevant record-keeping.

He said Sunair was working with the authority.

“They’ve been incredibly helpful. It’s not a combative environment.”

Sunair had charter flights, scheduled passenger services and flight training services, Roberts said.

It flies to Aotea/Great Barrier Island, Gisborne, Hamilton, Kaitāia, Napier, Tauranga, Wairoa, Whakatāne and Whitianga.

“We’re still able to provide a significant number of services, albeit with another operator in the interim,” Roberts said today.

“Most of our services are concentrated around Northland, Waikato, Bay of Plenty and the East Coast.”

Air Gisborne was operating some of those services.

Aotea/Great Barrier Island is one of Sunair's destinations. Photo / Chris Morton

The CAA said it was responding to aviation-related concerns regarding Sunair.

The suspension would run for 10 working days to Wednesday July 23.

“These concerns relate to maintenance and safety of their aircraft,” a CAA spokesperson said.

“The director of Civil Aviation has suspended the airworthiness certificates for aircraft operated by Sunair Aviation Ltd for safety reasons while we address these concerns.”

They said Sunair normally operated under Civil Aviation Rules Part 119 and under Part 135, which related to commercial helicopters or small aeroplane operations.

“We are working with Sunair Aviation Ltd to address the safety concerns, which will help inform our next steps.”

Aviation Industry Association chief executive Simon Wallace said: “It’s in everyone’s best interests that they get flying again once these matters have been resolved”.

In late 2017, the CAA grounded the airline and Sunair updated maintenance records and completed some remedial maintenance activities.

More recently, several regional airlines have described facing multiple pressures.

Air Chathams in April considered withdrawing its Whakatāne to Auckland route after losing more than $1 million in two years

Sounds Air chief executive Andrew Crawford told RNZ his airline had to ditch its Taupō and Westport routes and sell an aircraft.

But Roberts said he did not feel his regional airline was being picked on.

“There are various levels of operating certificates. You’ve got the major airlines and then you’ve got the next level down, like Sounds Air, and then you’ve got ourselves.

“The demands are appropriate for our levels.”