Forgive the laymen for asking a stupid question: wouldn't it make sense to use accelerometers and gyroscopes to help to determine the attack angle and speed? Isn't a gyroscope a standard equipment in a cockpit?
It doesn't quite work like this. A gyroscope is set to a point in space and will always track that point. An artificial horizon will always show relative to the horizon. Angle of attack however is different as it has no bearing on the actual angle to the horizon. To explain this a little better, I shall go into a bit of detail and mention a little bit of aerodynamic theory.
Usually, a wing generates the most like with the least drag at about a 4 degree angle of attack (AoA). This is handy to know. When an aircraft starts its takeoff roll, the wing will usually be about 4 degrees above the horizon. As you are rolling along the ground (assuming its perfectly flat), this 4 degrees is perfect for maximum lift.
This changes when the aircraft raises its nose. The AoA increases (usually to 10-14 degrees) at rotation, but as the relative airflow changes to the aircraft climbing, the AoA will drop back to about 4 degrees. At this point, the aircraft nose will *still* be 10-14 degrees nose up. As the airflow is not parallel to the earth (as the aircraft is now climbing) it is quite different to the pitch of the aircraft.
For this reason, it is impossible to get an AoA from a gyro - you need to measure exactly where the air is coming from - not the pitch of the aircraft.
