Chemmy Alcott breaks leg at Lake Loiuse

British skier Chemmy Alcott broke her leg when she crashed at high speed in downhill practice in Lake Louise in Canada on Thursday.

The 28-year-old landed badly after a jump in the tricky Coaches Corner section.

The Londoner was helicoptered off the mountain and taken to hospital in Banff where she is set to have surgery.

"It was brutal and the impact was serious. She broke her shin and another bone could be fractured," said race director John Cassel.

Starting from 50th position, Alcott went airborne over the first jump and never regained her balance.

Some of the racers, including World Cup overall champion Lindsey Vonn, were critical of the course in the lead up to Friday's downhill.

Defending downhill champ Vonn complained Thursday about icy and dangerous conditions on the course, which was made slick after organizers "injected" it last week by using high powered water guns to compensate for a lack of snowfall at the Rocky Mountain resort.

"It is a lot more icy," Vonn told AFP after her training run Thursday. "Conditions change from time to time. Sometimes it is grippy sometimes it is icy. You just don't know what to expect.