INDIANAPOLIS (AP) Three big crashes in Indianapolis 500 practice this week have raised one big question. Are the new oval aero kits, along with speeds that have topped 230 mph, the cause?
''We're still learning, to be honest,'' Helio Castroneves said. ''There are so many little details with the new aero kit that we're just starting now to go through that phase. My teammates are going through that phase as well and we're just starting.''
The three-time Indy 500 winner lost control of his car before it hit the wall, went airborne and flipped Wednesday. On Thursday, Josef Newgarden flipped his car in the latest crash.
Newgarden, the 24-year-old Tennessee driver, was checked, cleared and released from the speedway's medical center.
Team Penske's Simon Pagenaud led Thursday's practice with a fast lap of 228.793 mph.
Colombia's Carlos Munoz had the second-fastest time at 228.126, American Sage Karam was third at 228.126, New Zealand's Scott Dixon was fourth forth at 227.634, and Brazil's Tony Kanaan was fifth at 227.527.
Newgarden lost control of the CFH Racing entry car going into the first turn at Indianapolis Motor Speedway and the car flipped and rested on its side after it slapped into the wall.
''I'm still trying to gather my thoughts from it,'' he said. ''It definitely surprised me. Just lucky that everything's good and the Dallara tub held up pretty well.''
That seemed to be a common theme at Indy on Thursday as IndyCar and Chevrolet worked to determine if the new oval aero kits were the cause of a crash that sent Castroneves' car airborne Wednesday.
Both Castroneves and Newgarden drive Chevrolet cars and both crashes were similar - they happened near the same part of the track, and both cars flipped when the car turned backward.
''It's definitely concerning,'' CFH Racing owner Ed Carpenter said. ''We haven't had cars doing that ever in my career. But there's a lot different this year. I don't know that we understand why it's going on at this point and really I don't know that we understand that it's just a problem for Chevy cars, either.
Pippa Mann is the only driver with a Honda car that crashed this week, but still takes full responsibility for the crash that sent her car spinning into the wall Wednesday.
''My crash, it didn't have anything to do with the aero kits at all,'' the English driver said. ''My accident would have happened with those circumstances with last year's aero kit, with the 2011 car. It was just one of those things.''
The cars have only been on the track for five days with the oval aero kits, including test day held on opening day at Indy.
After Castroneves' crash, Team Penske owner Roger Penske raised his concern almost immediately about the front wicker pinning the front of his car down as it went airborne.
Earlier, IndyCar made the wicker mandatory for the remainder of the season, but Thursday decided to make it optional because the oval aero kit was originally tested without the wicker earlier this month.
''We were asked to take it off so we did,'' Carpenter said. ''I thought it was kind of obnoxious because we just got asked to put it on about a month ago. There's certainly a lot of unanswered questions and hopefully we'll get answers to them in time.''
If the wicker had anything to do with Castroneves' crash, officials say it's too early to tell and Chevrolet won't comment until they complete their investigation into the cause of the two crashes.
The bottom line for Newgarden, though, is that so far everyone walked away from their crashes without being seriously injured.
''Every once in a while the car's going to have a hard hit,'' he said. ''But it looks like the car did its job and kept them safe. That's the biggest thing for me, that they're safe race cars.''