[wrench]

The video appears to show an accelerated stall at low altitude. Look at the vapor trails off the wing leading edge, and the indicated angle of attack. The wing was stalling. Conditions at the airshow site may have been hotter/higher and or more humid than practice conditions.

The aircraft is probably marginal in its ability to execute this manouver this close to the ground. High density altitude may have been the ultimate unduing.

[Gunrunner2]

Regarding the “accelerated stall”/snap-roll.

First off, the angle of attack/lift diagram associated with the classic “Hershey Bar” wing design does not apply when you are flying a narrow cambered wing. With a classic thick chamber wing---like civilians use and my trusty ol A-10---as you approach the stall you have a clear “stall” buffet just before a clean stall break and the aircraft quits flying. However, with narrow camber wings---like those in hi-performance fighters---you experience a stall buffet well before you actually stall the wing. During the airshow the pilot had the aircraft in a sustained hi-G turn and the jet would not have experienced a classic "accelerated stall" common with a thick camber. The aerodynamics would not allow it. Even if the pilot snapped the stick back into his lap, as the jet would not have slowly rolled and dropped off, it would have "snapped" into the turn, the airspeed would have bled off immediately, and this would have been so noticeable that Ray Charles could have seen it.

A “stall” with a narrow camber is not a clean break and you do not have a snap-roll from it. In actuality, you fly narrow cambered fighters in a stall buffet on final approach, in the final turn, during loops, rolls and max-G turns---all done in a stall buffet (monitored by the seat of your pants---experience--and backed up by the AOA gauge).

Basically, you reach a "stall" earlier but you do not experience a stall-break like your average Cessna driver knows.

All that really happens when you reach the max point on the angle of attack/lift diagram on a narrow cambered wing is the nose stops tracking. . .you have no clean stall break.

But not to worry, the SU-27, like most all advanced fighters has a wing design where the wing will stall from the root outward, leaving the ailerons functional until well into a deep stall. And that, my friends, gives me reason to suspect the "accelerated stall"