I read most of this thread and I agree — it looks like Leeward passed out on an unexpected high-g pullup and the airplane was out of control from that point onward.
I wouldn’t have thought the loss of a trim tab would cause a high-g pullup but the testimony of the other ‘unlimited’ pilot (Bob Hannah, 1998 Reno) changed my mind. Also there is the evidence of the tailwheel deployed, and the absence of the pilot’s profile in the canopy in one shot, and appearing to be slumped forward in another shot.
This talk of 20 g’s on the airplane is ridiculous. That would exceed the ultimate stress of the airplane, without a doubt, and the airplane would have broken apart.
It doesn’t take all that many g’s to black out a pilot, if the pilot can’t anticipate the onset. Normally when you pull g’s you are the one making the control inputs, so you know exactly when to tense your legs and abdomen, among other things. But if it happens suddenly you can suffer g-loc (g-induced loss of conscousness) very quickly — so quickly you won’t remember it happening (assuming you survive). A sudden 7 g’s or more could induce g-loc. This event was probably in the neighborhood of 7-9 g’s, judging from Bob Hannah’s recount of a similar experience.
http://www.avweb.com/eletter/archives/avflash/2010-full.html#205390
“A sudden 7 g’s or more could induce g-loc.”
I would also point you to post 103 in this thread. If that picture is an actual race condition, a lot of what the pilot may have gone through is obvious. He is leaned forward, looking down and to the left. There is no apparent padding on the bulkhead behind his head. It he was hit with a sudden and unplanned even 4 or 5 g pull up, the effect on him would be much greater.
This is one of the reasons that the seat belts on modern airline aircraft have to be stressed for 16g while the attachment of the seat is only stressed to 9g. If a person’s body is allowed (by slack in the restraint system) to accelerate after the force is applied, the resulting impact to the person will be greater than the force applied to the aircraft (hence 16g’s for the belt, 9 g’s for the seat). I hope the photo in 103 was just some publicity shot and not the actual final configuration he raced in. He is in no posture suitable to absorb any kind of sudden g load in that photo.