RE: Rate Gyros for Automatic Control
Do not try any airplane attitude control using gravity as a reference (inclinometers etc.), because it will not work. Attitude control requires either inertial references (gyros) or reference to objects fixed in the earth's frame of reference (horizon, ground, etc.).
The inertial references (gyros) either recreate a fixed reference relative to the earth (attitude gyros - artificial horizons), or they provide information about motion relative to the earth (rate gyros).
If you put an inclinometer in an airplane, such as a glass of water, and you do a balanced turn, the water level would not change at all and so would convey no information relating to the attitude or motion of the airplane.
The human balance organs are inclinometers with angular acceleration sensing (note: NOT angular rate sensing). This is why humans cannot fly in cloud without reference to instruments. If you try you die, EVERY time!!!