A Christchurch woman travelling on an Air New Zealand plane forced to make an emergency landing today said everyone on board stayed calm through the drama.

Shona Powell was on the flight to visit family in Invercargill for the long weekend.

She realised something was "strange" when the plane veered away from the city.

"The pilot then came on and said there was a technical problem. One of the controls on the engine had frozen, I think was the word he used," she said.

The pilot said one of the engines would be shut down but assured passengers not to worry, she said.

"Everyone was very calm. I think we all know planes can fly on one engine."

The plane circled in the air several times before landing, Powell said.

Prior to touching down, the cabin crew advised there would be a "welcoming committee" of emergency services on the ground, she said.

"The entire crew were wonderful and very professional.  We were kept fully informed about the problem and what was going to happen which was much appreciated ... because the crew were calm we were too."

Invercargill Airport general manager Chloe Scala said the plane had landed safely after notifying authorities it had only one working engine.

Police, ambulance and fire crews responded to the emergency call but were not needed.

The flight left Christchurch at 10.15am and landed in Invercargill at 11.51am.

An airline spokeswoman said the Mount Cook Airways flight landed "without incident" after the pilots encountered a problem with the aircraft controls relating to one of the engines.

"The pilots took the decision to shut down the corresponding engine and the aircraft made an uneventful landing," she said.

 The flight was NZ5061 from Christchurch to Invercargill and had 46 passengers. 

A witness at the airport said disembarking passengers looked fine.

- © Fairfax NZ News