Why does this work:
flyer.rigidbody.AddRelativeForce (0,trueLift,0);
transform.RotateAround (targetPlayer.transform.position, Vector3.right,-truePitch);
flyer.rigidbody.AddRelativeForce (0,trueLift,0);
transform.RotateAround (targetPlayer.transform.position, Vector3.up,trueYaw);
flyer.rigidbody.AddRelativeForce (0,trueLift,0);
transform.RotateAround (targetPlayer.transform.position, Vector3.forward,-trueRoll);
But this does not:
flyer.rigidbody.AddRelativeForce (0,trueLift,0);
transform.RotateAround (targetPlayer.transform.position, Vector3(1truePitch,1-trueYaw,1*trueRoll));