The McLaren Formula One team says Fernando Alonso is "OK and conscious" after being involved in a heavy crash on the final day of pre-season testing in Barcelona.
The Spaniard, twice world champion, hit the wall on the exit of Turn Three at speeds of up to 240 kilometres per hour.
The 33-year-old was taken to the circuit's medical centre for initial treatment before being airlifted to hospital for precautionary checks.
Built-in alarms in Formula One cars measure the G-Force of crashes and FIA rules dictate that drivers must complete mandatory hospital tests if a certain reading is exceeded.
A McLaren statement says Alonso's car left the track at Turn Three, causing the right-hand side of his car to strike the wall.
It says he was conscious and spoke with the doctors but was then airlifted to hospital where he is undergoing precautionary checks.
The Circuit de Catalunya Tweeted: "It seems that Alonso is ok. We hope that everything's alright and all ends with just a shock!!"
It is not yet known whether the crash was a result of a driver error or a malfunction of the car.
Alonso's former Ferrari team, whom he left at the end of last season, Tweeted: "All the best Fernando."