Cape Town - McLaren's Fernando Alonso is "ok and conscious" after being involved in a heavy crash on the final day of pre-season testing in Barcelona on Sunday.
The Spaniard, twice world champion, hit the wall on the exit of Turn Three at speeds of up to 150 miles 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.
"Fernando Alonso crashed in the end of Turn Three. The car has gone back and crashed into the wall," a statement from the circuit said.
Built-in alarms in Formula 1 cars measure the G-Force of crashes and FIA rules dictate that drivers must complete mandatory hospital tests if a certain reading is exceeded.
"Fernando Alonso's McLaren-Honda car left the track at Turn Three, causing the right-hand side of his car to strike the wall," McLaren said in a statement.
"Fernando was driven to the circuit's Medical Centre where the circuit's doctors gave him first aid.
"He was conscious and spoke with the doctors. However, as per usual procedure in such circumstances, he 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."