But last Friday, it took "considerably longer" for arriving passengers to disembark and for departing passengers to board.
Then a passenger's bag was loaded on to the plane, but they did not turn up at the gate.
An Air NZ spokeswoman said the flight was due to depart before the curfew, but the missing passenger triggered the airline's standard procedure of "searching for, and offloading, bags".
That meant the plane had no hope of leaving before the curfew, forcing the flight to be cancelled, and passengers to disembark.
Air NZ staff then scrambled to find accommodation for the passengers, but given the late hour, and capacity issues in the resort, could not.
Auckland's Nannette Cadwallader was one of a few stranded passengers who found accommodation at Queenstown Country Lodge, but about 100 others had nowhere to go.
Sowry said that was when the airport company made the "extremely rare" call to stay open for the night and allow people to sleep over.
"Very obviously, that's not ideal. Our preference would be that people are able to be accommodated comfortably in a hotel room."
Ordinarily, it was the airline's responsibility to take care of their passengers, but Sowry said his team went "above and beyond" to help where they could.
"We are a reasonably lean team here at the airport company and, ordinarily, we're not resourced to have teams on standby in this sort of situation.
"But we did everything we could to make people comfortable, and then there was security on site overnight, just to ensure that people had access to the amenities they needed.
"I'm really proud of our team and the way that they stepped up ... that has been a lot of pressure and stress on our team, and it was a difficult situation and the wellbeing of our team is an absolute priority ... they responded, I think, very, very well."
Cadwallader said Air NZ rebooked her — but she would have had to stay in Queenstown until yesterday.
"I've got a family, I've got children I need to get back for, you know."
Instead, she paid extra to book a seat out last Saturday with the two friends she was travelling with.
However, when she got to the airport that morning, she learned she had been "bumped" from that flight, while her friends had not.
During a subsequent four-hour wait in a queue, a bus full of passengers left, bound for Christchurch.
When she finally got to the front of the line, she expressed her sympathy to Air NZ staff who, she said, were doing a "great job".
One thanked her and told said there had been "a couple of staff in the back in tears because it was such a disaster", she said.
By then, the national carrier had organised an empty plane to transport remaining passengers back to Auckland, which took off at 6pm.
It was about a quarter full.
The Air NZ spokeswoman said that was not unusual, given the "range of options for customers to choose from".
She said customers were advised the airline would reimburse up to $250 per room for overnight accommodation.
