Pictures: Checa bins RCV!

Carlos Checa made a nightmare Honda debut during Wednesday's opening day of testing at Valencia, when the former Ducati Marlboro rider fell from his Pons run RCV at high-speed (pictured).

The accident occurred on just his third lap of the Spanish circuit, which was hit by cold, windy and then wet weather conditions today - hampering much of the on-track action.

Checa suffered chest injuries during the fall, but was later given the medical all clear and returned to the track.

The #7, who has been replaced at Ducati by Sete Gibernau, has yet to be officially confirmed as a Honda Pons rider for 2006, but is expected to partner Casey Stoner at the team.

"Today we have been working with Carlos Checa and Casey Stoner preparing for the new season in 2006," said Honda Pons team principal Sito Pons. "Both riders have shown great potential with the RCV and have adapted to the machine very quickly.

"Carlos had a crash this morning but returned to the track in the afternoon and set some good times... I'm quite happy with both riders and look forward to testing with them," he added.

MotoGP rookie Stoner finished the day a very impressive fourth fastest, just 0.6secs behind pace setter Nicky Hayden, with Checa fifth.