A pedestrian was taken to the Royal Sussex County Hospital, Brighton, after an accident at Nutley.
The patient was taken to a specialist neurological unit by the Kent, Surrey and Sussex Air Ambulance.
The helicopter landed in a nearby sports field after it was called around midday on November 23.
Sussex Police and South East Coast Ambulance also responded to the road accident.
The Kent, Surrey and Sussex Air Ambulance Trust provides a Helicopter Emergency Medical Service (HEMS), responding to patients who have suffered trauma or serious medical emergencies.
It operates 24 hours a day, ensuring we can be there for the most critically ill and injured people in the region
As a charity, it relies almost entirely on donations and fundraising, and without this support, simply could not continue the life-saving work.