Passengers on Air New Zealand flight NZ5018 have told of the moment the plane started juddering and flames could be seen coming out of an engine.

Seventy-one passengers and four crew members were on the flight when the engine trouble began about ten minutes after take off from Napier airport.

Stacey Smith was sitting right by the left engine when the plane started juddering and "spitting fireballs".

He said the plane had just gone up and after about ten minutes the left engine stopped and they started coasting.

"I wasn't scared I was just having yarns with the people on board."

Karuna Chawla was sitting next to him. The trauma proved too much for the Aucklander who burst into tears as the situation unfolded.

Another passenger John Roberts said engineers had been consulted before take-off.

"About 3 minutes into the climb there was a loud bang, vibrating then flames and smoke- suffice to say as we were out over the sea there were some worried people albeit all stayed calm.

"The Air NZ staff were brilliant- calm and reassuring. We then circled over the sea for 20 minutes on one engine then came back into land at Napier- safely thank goodness."

Passenger Nicholas Chang said: "They told us to stay calm."

"The crew were great. The pilot reassured us and told us what had happened – that we had engine failure and were gliding smoothly on one engine."

A local resident who did not wish to be named said they heard a "very loud spluttery noise that sounded like a really old plane spluttering and the cats freaked out." She said they went outside and saw the plane as it was taking off.

"We could see large sparks of orange as it headed south. We watched the plane circle round until it disappeared over the coast and then we saw it head back."

Another resident whose house is on the flight path said they were used to planes overhead but this time it wasn't right.

"This one sounded wrong - way to loud, irregular and rough for the usual noise a plane makes. I went outside and saw the plane. It was really loud and flying towards the sea. My husband rang and he'd also just seen it fly overhead," the resident said.

"You could hear the plane from a distance. It was an unusual sound almost like a helicopter - sort of a cracking banging sound. You could hear it before you saw it. It was an awful sight. I could see flames coming out of the back of the engine and I could see the other propeller working and I hoped it would be able to land on one.

"It was lower in the sky as well - it must have only got up so high when they started having trouble and didn't have the power to get up any higher before they started turning."

An Air New Zealand spokeswoman described the situation as an engine surge shortly after take-off.

"This resulted in the fuel burning unevenly leading to the engine back firing, similar to what you might experience in a car.

"The engine was shut down and the aircraft landed without further incident."

The pilot of the ATR72-500 was trained for this scenario and the plane is designed to operate safely with one engine.

"Engineers have since checked the aircraft and confirmed there was no fire, and no visible damage to the engine."

More to come.