The early versions weren't so much of a flight simulator as a first person camera with plane-like controls and trivial physics. I'm sure they had a first person

The early versions weren't so much of a flight simulator as a first person camera with plane-like controls and trivial physics. I'm sure they had a first person camera already for debugging and then just stuck a couple force calculations on top just for fun. For anyone who has done a 3D video game or simulation before, F=M*A level newtonian physics can be implemented in < 1 hour.