Pilots are calling for mask wearing to be made compulsory on all flights immediately.
The New Zealand Airline Pilots Association has been calling for mandatory use for months and restated the plea today after the latest Covid-19 scare in Auckland.
"I struggle to understand why they're not mandatory on all forms of public transports - taxis, buses and planes," association president Andrew Ridling said.
Epidemiologist Michael Baker today also repeated his call for compulsory mask use on planes and other public transport.
The requirement to wear masks on planes was dropped by the Government when Auckland moved down alert levels after the August resurgence although masks are encouraged and compulsory use is being reviewed as part of the response to the latest community case of Covid.
In an Instagram post this week, Prime Minister Jacinda Ardern said: "I still encourage everyone to keep up the mask use on planes."
Ridling said the Government needed to go further.
"I think it should happen now," said Ridling, who had just flown from Christchurch to Auckland this morning on a flight where about half the passengers were wearing masks.
Ridling said masks would help prevent stepping back to requiring social distancing on passenger planes. On jets, this meant not selling the middle seat, which made the economics of running flights marginal and threatened airline profits and more jobs.
An airline group is calling for a consistent approach.
The Board of Airline Representatives (Barnz) says it strongly supports the use of masks by passengers as an important measure in the fight against Covid.
Airlines in New Zealand follow the Ministry of Health guidelines, which reflect their assessment of the level of risk faced.
During the previous Auckland outbreak, masks were mandatory on board aircraft for any areas under alert level 2. Under alert level 1, airlines continued to strongly encourage the use of masks, which were made available for passengers, executive director Justin Tighe-Umbers said.
"In the event of any other future flare-ups I'd expect to see this approach continued, with compulsory mask use a requirement onboard aircraft under alert level 2," he said.
"Shifting to mandatory mask use under alert level 1 is a call for the Ministry of Health experts based on the risk they see, and the Government also has to consider a consistent approach across all forms of public transport."
Air New Zealand says on its website that: "Masks are no longer required on board with Air New Zealand under alert level 1. Passengers are welcome to wear their own face covering and we will continue making masks available for those who wish to use one."
A number of studies have shown modern aircraft cabins to be safe compared to other indoor spaces, but Ridling said there were other stages of the journey for passengers where masks could protect travellers.
This week, the United States Centres for Disease Control and Prevention released research that showed mask wearing not only prevented respiratory droplets from spreading and potentially infecting other people, but also protected the wearer.
Masks made with multiple cloth layers have been shown to prevent 50 per cent to 70 per cent of a person's respiratory droplets from spreading to others. They could also reduce the amount of infectious droplets the wearer was exposed to, because the fabric barrier filtered out a degree of particles, CNBC reported.
Some data has shown that a multi-layer cloth mask made from a fabric with a high thread count could filter out nearly 50 per cent of respiratory droplets.