Watch a report by Stuart Leithes
Watch footage from an Air Ambulance in flight from 'Your local Air Ambulance'.
The air ambulance charities which cover the two counties say the new aircraft will give medics better access to patients and able to carry more equipment.
The launch represents an investment of more than £30 million by the charity over the next seven years and is the culmination of an 18-month project to modernise and replace the fleet.
The two ambulances will be used by the Warwickshire and Northamptonshire Air Ambulance and the Derbyshire, Leicestershire and Rutland Air Ambulance.
The new state-of-the-art AgustaWestland 109SP aircraft were unveiled at Sywell Aerodrome in Northamptonshire.
They are the next generation of Helicopter Emergency Medical Service (HEMS) aircraft.