IndyCar's official report into the fatal accident at Las Vegas Motor Speedway in October has been published, concluding that several factors occurring together in the worst possible combination resulted in the death of Dan Wheldon.
"There are multiple factors that are not uncommon to racing that came together in a way that claimed Dan's life," said Brian Barnhart, IndyCar's President of Operations. "It is a tragedy. Our thoughts and support will always be with Dan's family."
While the report did not find that high-banked ovals in themselves are unsuitable for IndyCar racing - "IndyCar and CART/Champ Car have successfully conducted numerous races over numerous years on courses that meet the definition of high-banked ovals," the report said - it was clear that the main factors had been an interplay between the existing Dallara chassis and the current Las Vegas Motor Speedway configuration that had been at the root of the accident.
"Due in part to the geometry of the track, each track has its own unique routes around the circuit that optimize speed and handling capabilities," the report explained. "These routes are considered 'racing grooves' and create restrictions on where a driver can place the race car on the track to remain competitive. Most tracks have limited numbers of racing grooves. For example, it is not unusual for ovals to have only one or 2 racing grooves, including the Indianapolis Motor Speedway."
But in the case of Las Vegas Motor Motor Speedway, it emerged from analysis of the video playback that the variable-banked, multi-grooved and recently repaved surface offered an almost limitless freedom for drivers in the existing Dallara chassis to manoeuvre at full speed almost anywhere across the track during the race, and still be competitive. Combined with the expected close 'pack racing' seen on race day, this was what led to the instability that produced the first accident, the report by independent forensic crash investigators suggested.
"While this incident could have occurred at any track at any time, the dynamic of the current car and the overall track geometry at Las Vegas Motor Speedway under race conditions appears to have been causal to this incident," the report stated.
"What was evident in the Las Vegas event was that the entire racetrack was useable and the lanes were limitless," added Barnhart. "That was a variable that had not been seen before."
The report added that this hadn't been possible to detect in advance during the standard formal two-day compatibility and performance tests at LVMS on November 15, 2010 conducted by drivers Scott Dixon of Target Chip Ganassi Racing and Ryan Briscoe of Team Penske, or the private testing by IndyCar and Firestone Indy Lights teams that had followed. The multi-groove characteristic only emerged as teams fine-tuned their set-ups during the practice and qualifying sessions during the race weekend and started to race in packs at increasing speeds.
The immediate cause of the accident was contact between the #06 (James Hinchcliffe) and the #17 (Wade Cunningham) as they entered the first turn on lap 11. The right front of the #4 (JR Hildebrand) then made contact with the left rear of the ailing #17 which is what finally triggered the multi-car crash.