Footage has emerged of fuel being dumped from an Air New Zealand plane that had to turn back on the way to Samoa this morning, sparking an emergency at Auckland International Airport.

Passenger Libby Middlebrook filmed the "bizarre sight" on her phone from the window of the plane.

Middlebrook was on the flight with her family, including two small children, when a "very professional and calm" voice came over the loud speaker.

"The pilot said in a very calm voice that there was an issue and we would be returning to Auckland," Middlebrook said.

"They said they needed to dump fuel because the plane would be too heavy to land."


Middlebrook said the plane did a "beautiful and smooth turn" and they flew back to Auckland with no further issues.

"The staff did an amazing job and came by to check the children were alright and happy."

"The only bizarre sight was watching the fuel being dumped before we could return to Auckland."

Fellow passeger Andrea Leask said crew told them they would see "some mist" out the window as the fuel was dumped.

"The crew were fabulous at keeping everyone calm and informed and there was no panic at all," she said.

Passengers were warned that they would see emergency services when they touched down but were told this was standard procedure and there was no reason to be concerned.

The flight - NZ296 from Auckland to Apia - returned to Auckland Airport after pilots detected an engineering issue shortly after take-off.

The pilot is understood to have declared an emergency but Air New Zealand said the aircraft landed safely around 9.50am.

There were 293 passengers on board.

Air New Zealand said a small amount of hydraulic fluid caused by the engineering issue dripped onto the hot brakes after the aircraft landed, causing smoke.

The airline said some witnesses on the ground wrongly interpreted it to be a fire.

About six fire crew and other emergency services responded to the incident and the runway was temporarily closed, delaying some flights.

Air New Zealand is investigating the incident.

A passenger on the Boeing 777 tweeted that the plane was flying to Samoa but a decision was made to turn around, dump fuel and land.

They posted a photo from the aircraft window of an emergency vehicle driving towards the aircraft on the tarmac.

The replacement flight is due to leave Auckland at 1.30pm.