Piper crop spraying type crash in Mexico.

[fdr]

That is a pretty unfortunate what to end the day.

From the start of the pitch up, the aircraft achieves an attitude change of around 20+ degrees, (needs measurement to determine the aspect change) but that happens in... ~11 frames of a 30-FPS image but he looks of it, and that is a pretty impressive pitch attitude change angle, the rate is much more impressive. The load on the aircraft is related to the resultant normal force which comes from the angle of attack that is applied. The angle of attack is analogous to the difference between the instantaneous pitch and the flight path vector. Normally we consider steady state conditions and these are not, this is a dynamic pitching case, and the usual assumption that the wing will stall at a certain angle of attack and that will limit the normal force that may be derives is not quite correct.

Unsteady effects are generally assumed to start to feature when a change in state occurs within the time that the flow takes to travel the chord of the airfoil. That has been the considered case, however, research on dynamic pitching of rotor blades shows that the effects occur outside of that assumption, and they alter the characteristic curves of CL, CD and CM vs AOA significantly. Where a wing may stall at say, 15 AOA normally, dynamic pitching will delay stall and values well above 20 AOA will still result in increasing CL, and therefore over short periods normal force from the wing. The video shows that the flight path is changing, and that rate of change comes off the pitch change to give eventually the steady state AOA. In FBW systems from the F16 through A320 and B777, there is a pitch rate ramp up that is achieved. For a fly by cable design, the elevator deflection is essentially instantaneous to the control input by the pilot, the rate is purely dependent on the drivers physiological arm motion limits. Dynamic CL, CD and CM are spectacularly different to the assumed vanilla steady state charts of characteristic CL, CD, CM to AOA, and are subject to biggly hysteresis, CL ends up looking like an italic P that over lays and extends beyond the inverted U [sine] of the CL curve; CD ends up looking like a drunk oblate spheroid, a flattened O with the case of the leans, and instead of mainly being a slightly increasing negative line until a fairly abrupt shift to positive, CM looks like a scribbled letter T, inked by someone with a bad dose of MND)
Pulling abruptly might be good for lawn mower starters, but is not great on planes. Actually, it isn't good for lawnmowers either.

AA 587 resulted from an sequence of inputs that just had to be about as unfortunate a career move as is conceivable. While nasty, in isolation each input would not have resulted in a bad day, but the sequence resulted in a rapid increase in bending and torsion loads, alternating direction and being exacerbated by the resultant yaw which lags. Even then, one of the fundamental badnesses was the structure of the tail had a primary and secondary load path as is needed by failsafe design, but the failure of one results in an effective lever load applied to the other that exceeds its isolated load limit at the same time. The force limiting of the A300-605 in common with the OEMs practice is a throw limiter which results in an increase in sensitivity compared to a limiter that reduces the hydraulic pressure applied, but allows the full movement of the rudder pedals.

The LE translates upwards while the TE initially stays near the normal geometry, so the outboard fitting of the forward compression strut would be interesting to look at. Once it fails, the torsion as well as the rolling moment resulting from the geometry change is going to lead to a rapid bad day.

Be gently on the onset of control inputs, someone else might have been as rough as we are, most materials have a really long memory, and planet earth doesn't give way for aircraft.

Did the wing fail prematurely? I suspect... not. The PA-25 by recollection has a 4412 equivalent airfoil, which has a fairly soft stall break, dynamic pitching will lead to much higher CL than expected before the section stalls, so it is possible to get higher instantaneous loads. The forward fitting will show a compressive/buckling failure, but, there could be prior damage, a close look at the components will tell the story. That the strut gave way in the sequence is on the video, the question is why did it start to buckle. If you really need to hit hard pull ups, go do it in a Pitts or Extra, not in a normal or utility category aircraft I would suggest.