You are not permitted to download, save or email this image. Visit image gallery to purchase the image.
New Zealand Air Line Pilots' Association president Andrew Ridling said masks would reduce the need for people to be separated on planes.
"It's difficult to achieve such a high degree of social distancing unless the aircraft [loading] is so light that it becomes uneconomical to fly the aircraft."
He said airlines could give out masks at departure gates, as some American companies are doing.
"I think the idea of getting people to wear masks is all about getting some social understanding that there is no increased risk."
He said it would still be safe for passengers with less spacing. People were sitting facing forward, the air was highly filtered, and the air flow in a plane's cabin was vertical, he said.
University of Otago epidemiologist Professor Michael Baker said masks were now recommended in most of the world and should be worn on public transport.
He told RNZ's Morning Report programme the US Centre for Disease Control and the United Kingdom's health department were recommending masks for public transport.
"It has the huge benefit in that it means you don't have to have any empty seats on buses and planes."
Baker said masks would become the norm on planes, and may prove more important than hand washing in controlling the spread of Covid-19.
Director-General of Health Dr Ashley Bloomfield said they will be looking into what role masks may play].
"We are considering the role of masks on public transport and on flights as well but I think the best protection for people wherever they are ... is for us to not have the virus in the community circulating around.
"So any decisions about use of masks are alongside other key things like retaining physical distancing and so on. So yes, masks may play a role.
"We're less than a week into alert level 2 where people are now able to fly around the country, so we're still finding our way and easing into that, but we will be looking into the role of masks."