IndyCar has released its report on Dan Wheldon’s fatal accident in the IndyCar Series finale at the Las Vegas Motor Speedway two months ago.

The report concludes that Wheldon was killed when his car struck one of the retaining posts holding up the track’s catch fencing. The impact tore a hole in the top of the car’s monocoque and hit Wheldon in the head, killing him instantly.

“The chassis impacted a post along the right side of the tub,” said IndyCar’s operations chief Brian Barnhart. “That created a deep defect in the tub that extended from the pedal bulkhead along the upper border of the tub and through the cockpit. The pole intruded in the cockpit and made contact with the driver’s helmet and head.

“That caused a non-survivable, blunt force injury trauma to Dan’s head. Dan’s injury was limited to his head. There was no evidence of mechanical or structural issues contributing to this accident. The Safer barrier and the fence system appeared to function as designed during the accident. The impact with the fence that resulted in Dan’s non-survivable injuries involved the circumstances of location, direction and orientation that was the chance result of previous interactions.”

In examining the crash IndyCar took data from the onboard accident data recorders and Pi data systems from each of the 15 crashed cars. A thorough examination of Wheldon’s car and helmet also took place and video and still photographs of the accident were studied.

The posts at the Las Vegas track are located inside the fencing and some critics have suggested this exacerbated Wheldon’s injuries. But Barnhart refuted those claims: “The fence appeared to perform as designed. There’s no indication whatsoever that had the fabric or mesh been on the inside that the outcome of this accident would have been any different.”

Running in 24th place in the middle of the pack of crashing cars, Wheldon had time to get off the throttle and on the brakes before hitting the tail of Charlie Kimball’s car, which launched him towards the debris fence. Wheldon had decelerated from 224 to 165mph before the impact, which measured 23g longitudinally and negative 23g vertically but wasn’t enough to do Wheldon any damage. However, the collision sent Dan’s car flying for about 325 feet before striking the fence.

IndyCar announced last week that it would not race at Las Vegas next year. But Barnhart and IndyCar CEO Randy Bernard said they would evaluate next year’s new Dallara DW12 to see if it’s possible to return to the track in the future. Barnhart said IndyCar is taking a close look at all the high-banked ovals where it races.

“Each oval has unique characteristics and should be considered individually,” he said. “The banking itself is not the only geometry taken into consideration. There are a number of factors including the length and width of the track, the progressiveness of the banking, the length of the transition and the overall grip or co-efficient of friction of the asphalt. There are a number of factors that should be taken under consideration on an individual basis, not simply by banking alone. IndyCar, CART and Champ Car have successfully conducted many races over numerous years on high-banked ovals.”

Bernard added that the 2012 IndyCar calendar will be released imminently while the first batch of 15 Dallara DW12s were delivered to teams in Indianapolis this week.