Spin aerodynamics need work in the sim

(https://drive.google.com/file/d/19Mr8zDr_z8WtnbGq39t9zAOyTwg1vPBK/view?usp=sharing)

The entry and incipient stages are accurate in the sim, but the plane should keep spinning towards the ground until I relieve rudder pressure, and then the nose should slowly rise.