The air ambulance has attended a two vehicle crash which has closed the A24.
An eyewitness told the County Times they had spotted the helicopter landing at the scene at about 5.50pm today, October 8.
The collision, between Buckbarn and Dial Post southbound, closed the road, West Sussex Fire and Rescue said.
Sussex Police urged drivers to avoid the area.
One person who was trapped in a car has been rescued, police added.
SECAmb has been approached for comment.