Use
The essential components of the indicator are:
- "miniature wings", horizontal lines with a dot between them representing the actual wings and nose of the aircraft.
- the center horizon bar separating the two halves of the display, with the top half usually blue in color to represent sky and the bottom half usually dark to represent earth.
- degree marks representing the bank angle. They run along the rim of the dial. On a typical indicator, the first 3 marks on both sides of the center mark are 10 degrees apart. The next is 60 degrees and the mark in the middle of the dial is 90 degrees.
If the symbolic aircraft dot is above the horizon line (blue background) the aircraft is nose up. If the symbolic aircraft dot is below the horizon line (brown background) the aircraft is nose down. When the dot and wings are on the horizon line, the aircraft is in level flight. Because it is the horizon that moves up and down and turns, while the symbolic aircraft is fixed relative to the rest of the instrument panel, trainees get confused; a standard corrective given by flight instructors is "Fly the little airplane, not the horizon."
A 45 degree bank turn is made by placing the indicator equidistant between the 30 and 60 degree marks.
The pitch angle is relative to the ground, which is not as helpful as knowing the angle of attack of the wing, a much more critical measure of performance. The pilot must infer the total performance by using other instruments such as the airspeed indicator, altimeter, vertical speed indicator, and power instruments, e.g. an engine tachometer. "Performance = Attitude + Power".
Most Russian-built aircraft have a somewhat different design. The background display is colored as in a Western instrument, but moves up and down only to indicate pitch. A symbol representing the aircraft (which is fixed in a Western instrument) rolls left or right to indicate bank angle.
It was proposed that a hybrid version of the Western and Russian artificial horizon systems to be developed that would be more intuitive than either.
Read more about this topic: Attitude Indicator
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