Wingsuit Equations first published on December 7, 2006:
http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=2563135
by Yuri

What are Wingsuit Equations

Wingsuit Equations are differential equations of motion governing wingsuit flight dynamics in two dimensions.
Simple and beautiful, they allow for high precision simulation of wingsuit flight by knowing sustained velocity alone.

When we think about modeling of wingsuit flight, the task at hand seems to be impossible to solve.
To calculate trajectory, one would need to precisely know forces acting on the body at any moment in time so that acceleration can be calculated.
Given initial velocity, one can then numerically integrate acceleration to obtain velocity at any moment, and then further integrate the velocity to obtain complete trajectory.
But how can we know the forces?

The aerodynamic forces acting on a flying body – lift and drag – are proportional to density of air, surface area, lift and drag coefficients, respectively, and the square of airspeed.
We do not know exactly what the surface area and lift and drag coefficients are, and the latter depend on the angle of attack and body position.
It seems, we cannot calculate the aerodynamic forces and thus cannot model the flight.

But with a little help of pure flying magic… we can!