The Attitude Indicator shows rotation about both the longitudinal axis to indicate the degree of bank, and about the lateral axis to indicate pitch (nose up, level or nose down). It utilizes the rigidity characteristic of the gyro. It is gimballed to permit rotation about the lateral axis indicating pitch attitude, and about the longitudinal axis to indicate roll attitude. Once powered up, the indicator is maintain in a fixed position no matter what the aircraft attitude may be.
There is also an adjustment knob used to adjust the wings up or down to align with the horizon bar. This allows adjustment to the height of the pilot. Preferably, the adjustment should be made when level on the ground. When the wings are aligned with the horizon bar, the aircraft is in level flight. If the wings are above the horizon bar, the aircraft is in a climb. Wings below the horizon bar indicates a decent. The upper blue part of the ball represents the sky. The miniature airplane wings (fixed to the case) represent the wings of the aircraft. In the past, the instrument has been referred to as "an artificial horizon". When in a left turn, the blue portion of the ball will have rolled to the right, as though you were looking at the horizon over the nose of the aircraft. In a right turn, the blue portion will have rolled to the left.
The rotor, mounted in a sealed housing, spins in a horizontal plane about the vertical axis. The housing pivots about the lateral axis on a gimbal, which in turn is free to pivot about the longitudinal axis. The instrument case is the third gimbal necessary for universal mounting. The horizon bar is linked to the gyro by a lever, attached to a pivot on the rear of the gimbal frame and connected to the gyro housing by a guide pin.
When the attitude indicator is in operation, gyroscopic rigidity maintains the horizon bar parallel to the natural horizon. When the pitch or bank attitude of the aircraft...
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