Air New Zealand has resorted to offering cash incentives of up to $1400 to entice people to work for the airline, as chronic staff shortages at airports cause travel industry turbulence.

The global aviation sector is scrambling to fill thousands of jobs shed when the Covid-19 pandemic grounded flights, with delays, cancellations and lost bags frustrating travellers overseas.

Air New Zealand slashed 4000 jobs during the crisis, but has since hired 3000 staff and is trying to recruit a further 1100 over the next few months.

In a letter to staff obtained by RNZ, the national carrier promises to reward employees who recommend a family member or friend for airport work in areas like baggage-handling and check-in.

"Refer a friend or family member and once they're successfully onboard, you will both receive $400 (gross). As an additional thank you, once the employee you recommended completes 12 months within Airports, a further $1000 (gross) will be paid to you both," the letter said.

Air New Zealand chief people officer Nikki Dines said the company wanted to hire 250 airport staff in the next four months.

"We're in a period of low unemployment, it's more difficult now to attract candidates, so that combination of high volumes of recruitment and a much more competitive labour market means that we wanted to go out with a really attractive offering to candidates," she said.

The offer, which runs until September, is in addition to the one-off $1400 cash bonus employees received in March to reward staff who worked during the pandemic.

It comes with a number of conditions - people can only refer someone if they are a New Zealand-based employee and must still be working for the airline at the time the second payment is due.

The letter notes the offer is "a pilot only due to the challenges we're facing in Airports around recruitment and retention".

Aviation industry commentator Irene King said cash incentives were almost unheard of in aviation recruitment, but pointed to a tight labour market and concerns around job security in the sector.

"You've got almost a flight away from aviation," she said.

"People are pretty wary of re-engaging with a sector where there's been such a massive downturn and the perception is it's not stable yet."

E tu head of aviation, Savage, said Air New Zealand usually had a line of people eager to work for the company but faced intense competition from other sectors offering more stable work with better pay and sociable hours.

"It's certainly an unusual situation when you're having to go out and turn all of your airport workers into potential recruiters to try to get people in the door," he said.

"It's relatively easy to find someone and attract them to the company, but being able to stop them leaving when other jobs come up is going to be the hard part."

Savage said there were hundreds of jobs vacancies at New Zealand airports, putting pressure on existing staff who had to plug the gaps.

"Some people are turning down overtime because they've already done too much work and they're fatigued," he said.

"There is a risk that airlines just simply will have to scale back on their schedules because they know that they don't have the ability to service the flights or turn those flights around fast enough."

Rigorous background checks for aviation workers meant the recruitment process was more complicated, Savage said.

While there was more pent-up demand for travel than predicted, Nikki Dines said Air New Zealand had a head-start because it had progressively brought back staff.

"Even though we didn't have any certainty about when borders would reopen, we wanted to make sure that we could get ahead of the game by bringing people back early," she said.

"So that, coupled with a slow and careful restart in terms of our scheduling, means that we're really making sure that we ramp up quickly but carefully."

Irene King warned airlines were likely to struggle with labour shortages for at least a year.

"It's a massively competitive labour market out there. I think we're going to have quite serious labour supply disruptions for at least 12 to 18 months," she said.

Air New Zealand has not ruled out expanding the scheme to include other parts of the business like cargo.

The airline is also trying to hire an extra 200 contact centre staff to help it deal with a huge increase in customer calls.

People have complained of hours-long waits for help with bookings, with Air New Zealand last night warning people on its website of a wait time of up to three hours.

The company expects to reach 75 percent of its pre-Covid-19 international capacity and more than 100 percent of pre-pandemic domestic capacity by the end of the year, according to its chief executive Greg Foran.