A motorcyclist was flown to hospital by the Westpac Rescue Helicopter after clipping a van and losing control of his bike near Te Aroha.

The rider -- a man in his 50s -- ended up in a ditch on the side of Te Aroha-Gordon Rd after hitting the van, sustaining injuries to his chest.

He was flown to Waikato Hospital for treatment.

The rescue helicopter was used as time was a critical factor in the man's survival.