A car has rolled down a bank throwing the female driver from the vehicle in southern Hawke's Bay this afternoon.

The incident occurred just after 12.30 today on State Highway 50 near Ashcott Bridge about 12km east of Waipukurau.

The Lowe Corporation rescue Helicopter airlifted the 47-year-old woman to Hawke's Bay Hospital after she was slipping in and out of conciousness.

The other passenger in the car escaped with minor injuries.