A new helicopter will serve as a 24-hour air ambulance for Kent, Surrey and Sussex.
The newer version of the helicopter based in Redhill will ensure the aircraft is ready for night flying in the late summer.
To prepare for the 24-hour service, the charity's specialist paramedic crew have already started delivering a medical service using a response car throughout the night.
Adrian Bell, Chief Executive of the Kent, Surrey and Sussex Air Ambulance, said:
"We have replaced one of our helicopters with a new version capable of night operations. While we are waiting for the necessary regulatory processes to be completed we have started operating by car during the hours of darkness."