"The captain met and debriefed customers in the terminal. They will now be transported by road to Wellington to continue their journeys," the spokesman said.
"Pilots followed standard operating procedures and requested emergency services be on standby for the landing."
People gather at Palmerston North airport as a flight is in trouble. Photo / Cameron Death
Cameron Death, who was waiting at Palmerston North airport for a flight, said there was "a lot of smoke" when the plane landed.
Passengers were immediately evacuated off the back of the plane and werestanding out on the runway, he said.
"The situation is that we have had a report of an aircraft with a problem and at the present time we are at the airport waiting for the aircraft," he said.
"There's a problem with unsafe landing gear."
The aircraft will remain on the runway until it has been inspected by engineers.
Customers booked to travel on the cancelled services can call the Air New Zealand Contact Centre on 0800 737 000 to rebook on an alternative service.
In light of the circumstances the airline is also offering full fare refunds, regardless of the fare type purchased.
If travel is not urgent or customers wish to request a fare refund there is no need to do so today as call centre demand may be higher than normal resulting in longer wait times.