A man has been airlifted to Palmerston North Hospital with serious chest injuries after being ‘‘rammed’’ by a sheep on a farm north of Hunterville.

Palmerston North Rescue Helicopter pilot Lance Burns said the man did not appear to have been trampled but had obviously been headbutted relatively hard by the sheep.

It was thought he was in a pen with the sheep at the time of the incident.

He stabilised by St John paramedics on board the rescue helicopter and arrived at Palmerston North Hospital in a serious condition.

It is the second sheep attack in the central North Island in the past year that has lead to people being hospitalised.

In May a woman was airlifted to Palmerston North Hospital with a serious leg injury after being knocked down and trampled by a mob of sheep at a remote Tararua property.

The woman, 53, was moving the sheep at her property in Huia Rd near Pongaroa when they knocked her over.

The sheep headbutt was not the only job for the rescue helicopter over the past two days.

On Thursday the chopper assisted at a motorcycle crash on the 42nd traverse track near Owhango where a woman suffered back injuries after coming off her motorcycle.

Once located, due to the dense bush, a St John paramedic was winched down to the track to the woman.

She was then winched into the helicopter and taken to Wanganui in a stable condition for further treatment.

The helicopter then responded to call to Waituna West for a 5-year-old suffering a medical emergency. The boy was taken to Palmerston North hospital in a stable condition.

The helicopter was also tasked by the police to assist in a search for five trampers in the Otaki Forks area.