Spanish Formula One test driver Maria De Villota was in hospital with facial and head injuries after her Marussia car hit a parked truck at an airfield in eastern England.
The Russian-licensed team said in a statement that the 32-year-old, who was driving the MR-01 car for the first time, had just completed an installation run at Duxford when she had the accident at around 0810 GMT.
"Maria is conscious and medical assessments are ongoing," the team said after she was taken to Addenbrookes hospital in Cambridge, the region's major trauma centre.
East of England ambulance service spokesman Gary Sanderson said the driver had "sustained life-threatening injuries".
The emergency medical charity Magpas said on their website (www.magpas.org.uk) that De Villota had facial and head injuries and was stable.
BBC Cambridgeshire presenter Chris Mann, who was at the Imperial War Museum-owned airfield for the straight-line test ahead of the weekend's British Grand Prix at Silverstone, said the car "inexplicably accelerated" into the back of the team's parked support truck.
"The driver's helmet was impacted on the side of the truck," he reported. "It just happened suddenly, a very shocking incident.
"The car slowed down as you see happens during a grand prix, for it to then be reversed into the pits which was actually a tent. But at the last second it just suddenly accelerated again so by the time it hit the truck, it was doing 30 or 40 miles an hour."
Mann said De Villota, 32, was trapped in the car for a considerable time with emergency services attending her immediately.
"It appeared to me she wasn't moving for about 10 or 15 minutes. We saw her move her hands after about a quarter of an hour and it took almost an hour for the ambulance (staff) to feel confident to take her out of the car."
The driver is the daughter of former F1 racer Emilio De Villota.
She was appointed test driver of Marussia in March, making her the only woman in such a role at the time although Williams have since handed a similar development role to Suzie Wolff.
De Villota has raced in various series and tried out a Renault Formula One car in August.
Marussia's race regulars are German driver Timo Glock, who missed the last grand prix in Valencia through illness, and Frenchman Charles Pic.
The British-based team, who were formerly known as Virgin Racing and have not scored a point since their F1 debut in 2010, have no reserve driver and De Villota lacks the necessary super-licence for the role.
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