Nhu,

I worked in the general aviation field many years ago and remember discussions about the "flat death spiral" for light aircraft and that there was no solution. Once it happens, you are dead.

However, I know that at least one manufacturer is making an airplane with a parachute. I can't help but think that this can get you out of the spiral and then you can release the chute. However, I am just guessing.

Good luck,

Steve

Thanks so much Steve F. Russell 

In the design point of view, if we know analysis methods, we can design to resist the spin of light aeroplanes  

This thesis gave the deep explanation and method for spin 

The Aeroplane Spin Motion and an Investigation into Factors Affecting The Aeroplane Spin

But still based on Vision Based State Estimation (VBSE) 

Recently, ICON 5 aircraft is designed well for spin resistance while the normal light aircraft encounters spin at the same low speed and high AoA 

One idea that is low cost is using Xplane 10's aerodynamic capabilities to evaluate.

how reliable does Xplane 10 simulate the spin mode? Do u know any case using Xplane to test for that?