The Sussex and Surrey air ambulance was called to the outskirts of Uckfield yesterday after a collision between a Land Rover and a motor-cycle at lunchtime.
The helicopter landed in a field next to the road and took a man, aged 62, from Burwash, to Eastbourne District General Hospital, with a head injury and broken leg.
South East Coast ambulance and Sussex Police were also on the scene.
Police are seeking witnesses to the crash in Palehouse Common Road, at the junction with Brookhouse Lane.
The 62-year old Framfield man who was driving the Land Rover was unhurt.
PC Matt Harman of the Sussex Road Policing Unit at Polegate, said: “We ask anyone who saw what happened to contact us via 0845 60 70 999 quoting serial 740 of 10 May.”
*The Air Ambulance service in Kent, Surrey and Sussex costs around £3.4 million annually to stay airborne. Receiving no funding from the National Lottery, the charity relies almost entirely upon the generosity of the public to support the two helicopters, based at Marden and Dunsfold.
Last month the Kent ambulance landed on the Manor Park Estate, Uckfield, to take a child to hospital after an accident.