My take on things:
First I'd like to say how badly I feel that spectators were injured and killed in this accident. As someone who barely escaped a similar fate at Flugtag '88 and saw my share of disturbing sights, I have nothing but sympathy for all those affected.
That said, I have an interest in analyzing and understanding the events that take place in aviation and this event is no exception. As a pilot, aviation mechanic and long time race fan who has attended 15 of the last 20 race years, I have more than a passing interest in this accident. To the "don't speculate, wait for the report" gang: Sorry, no dice. Well reasoned discussion of a technical nature is a different thing than wild uninformed speculation. Trouble is, only technically savvy people with good reasoning skills seem to recognize the difference!
My own analysis of the information available to me as of this date comes with the proviso that it is only a working theory and subject to modification by new facts or correction of any flawed theories or assumptions. We're not gonna hear much substantial analysis from the NTSB for quite some time. Consequently, I feel that some reasonable speculation among the more informed participants having a factual and/or supportable theoretical basis for their ideas is more constructive than might otherwise be proffered if these ideas were not offered for the purposes of discussion. So here goes my take on what's apparent so far:
Photos indicate that the trim tab on the left elevator became partially detached then departed the aircraft at some point in the sequence of events. It is logical to presume that the detachment of the trim tab would cause a significant change in elevator hinge moments and therefore the elevator control forces.
At very high airspeed, the trim would typically be adjusted pretty far in the nose down (tab T/E up) direction to counter the airplane's natural nose up tendency with increased airspeed. Removal of the trim tab induced force about the elevator hinge point would result in a significant change in the control force required to hold the elevator in the desired position. I would expect that an immediate and strong elevator trailing edge up (stick back) force would result from the loss of the trim tab under this condition of high speed flight.
When added to any force already applied, the gees could reasonably be expected to build faster than the human can react to apply forward stick before the onset of gee induced loss of consciousness. (As happened to Hannah in '98) What video of the sequence I've seen appears to indicate a rapid upward change in flight path somewhere west of the pits approaching the home pylon. At 500 mph, that rate of angular change certainly appears to me to be indicative of some pretty high "G" forces. Why Hannah's plane continued skyward and Leeward's rolled into a dive is open to conjecture, but that's the difference in outcomes it seems.
The video and still images seen so far appear to support the theory that the pilot was rendered unconscious during the pullup and exerted no control after that. Had the airplane not been rolling as well as pitching, there might have been more time for a recovery such as Bob Hannah's, but we'll never know.
I'll be interested to see if the NTSB opens a public docket so we can access some of the investigative work product prior to release of the final report as has been the case in many major accidents. The possibility that they may have some recorded flight parameters is intriguing will hopefully include good time reference, attitude and/or accelerometer data.
westhawk