Smooth glide for paper airplane

If you're thinking of building an aerodynamics engine, you have your work cut out for you!!. There has been some flight sim engines built for unity - you might wanna google for examples, but the way I would approach this would be to 'simulate' flight. e.g if it turns right slightly, apply relativetorque to turn it based on the angle - stuff like that. Are you doing this using physics / rigidbodies, or are you trying to do this using transforms?