The collision took place between a motorbike and a bus on the stretch of road outside RAF Wyton at about 9.15am. Cambridgeshire police closed the road while investigations were ongoing and the scene was cleared. East of England Ambulance Service (EEAST) paramedics were also at the scene, along with the air ambulance. A spokesman for EEAST said: The paramedics treated a patient who had suffered head and leg injuries, and has been airlifted to Addenbrookes Hospital, in Cambridge, in a life-threatening condition. It is expected that the road will reopen before 3pm.