Two calves had to be put down and a woman was flown to hospital with suspected broken legs after a crash south of Kaikohe.
Kaikohe fire chief Bill Hutchinson said the accident occurred about 2.10pm on Monday when a van towing a trailer loaded with calves left Mangakahia Rd near the aerodrome.
The van, which had been travelling north, crashed through a fence, across a paddock and into a large drain. The impact pushed in the front of the van, trapping the driver by her legs.
Two crews from Kaikohe Fire Brigade used hydraulic cutting equipment to free her.
For the first time in Northland two paid firefighters from Whangarei accompanied paramedics on board the Northland Rescue Helicopter in case they were needed to help extricate the driver.
The initiative to carry firefighters and extra gear in the chopper was launched last December.
Fire and Emergency New Zealand and the Northland Rescue Helicopter teamed up to get firefighters quickly to incidents where people need to be cut out for speedy medical care.
The helicopter crew fly St John Ambulance flight medics and two firefighters to incidents where people are trapped and this was the first incident where firefighters arrived at a scene.
Station officer Mark Wirihana and senior firefighter Brad Christensen joined the helicopter crew but just as the aircraft landed the Kaikohe fire team managed to free the woman.
"The volunteers on scene had done a great job, we helped with the patient and loaded them into the helicopter. It's just good to have an extra set of hands and eyes plus extra gear they might need," Mr Wirihana said.
Mr Hutchinson said at least half a dozen calves were in the trailer and two injured animals were put down by a local farmer. The woman was flown to Whangarei Hospital with suspected broken legs.