Helio Castroneves uninjured in airborne Indy 500 practice shunt

was running into Turn 1 when his car snapped around and made contact with the wall, launching tail-first into the air.

It completed a 180-degree flip and landed back on its wheels before sliding to a halt. Castroneves was able to climb from the car unassisted.

"The car was really good and I am very blessed," he said.

"Unfortunately I still do not understand what happened. I got loose in Turn 1 and spun out.

"The good news is the impact wasn't very strong and the landing was smooth as well. In all aspects, I have to say I was very lucky there was no big shunt.

"The accident was most impressive, but the good news is I am feeling very good. This just set us back one day since it is Wednesday.

"We still have Thursday and Friday before qualifying. I'm counting on my guys, my boys, to put the car back together and go back to work."

Team owner Roger Penske said that the crashed chassis will not be run again at Indy.

"We wouldn't run that car," he said. "We'll run a backup car."

IndyCar has made modifications to the cars during the off-season to minimise the likelihood of their becoming airbone, and Penske admitted that he was surprised to see Castroneves' car take flight.

"We're playing with new areas from the aerodynamic standpoint, and of course, going backwards at that speed, you don't know what kind of lift it had," he said.

"But obviously, it got airborne which we were surprised (about). We'll take a good look at it."