For me the key to this tragic accident is power reduction - especially in the first half of the looping manueuvre. No-one knows why this happened. In my opinion no display pilot whose brain is functioning normally would apply anything less than full power in the first half of a low-level loop - especially if entered slow. I believe something starts to go horribly wrong at 12:21:50, about 35 sec before impact.
At this stage he had positioned nicely and needed to accelerate for a few more seconds before pulling up, power is around 7700 RPM, its a nice day, no cloud, off-crowd wind, Lancing college to the right, only 20 degrees to bend during the loop... then there is a power reduction to less than 7000 RPM... that does not make sense.. he needs to accelerate.. Just before pull up power increases to 7500, but then around 2 sec later it reduces to less than 6700 before increasing to around 7200.. this is a really strange thing to do, and, I believe, a highly significant event that led to the low energy state at the apex of the manoeuvre.
I think it possible the pilot may have suffered some sort of transient 'cognitive impairment' .. Apart from the totally illogical power reductions, another clue for me is that with an off-crowd wind of about 15 Kts, with only 20 degrees or so to 'bend' - he rolled too much (about 60 deg) on the way up, that, too, does not make sense.
A
Transient Ischemic Attack could posibly explain this tragedy. A close relative of mine had one of these while driving a few years ago and described it as 'like waking up having just being born' while on a roundabout. It took about 20 sec to recover and never happened since.
I believe the possibility should be considered.