- A gyrosyn compass system has a remotely located unit for sensing the earth’s magnetic field. It incorporates a gyroscope to provide stability. This operation requires electrical power. A variety of cockpit indicators can be driven by a gyrosyn compass system, including fixed-card instruments or moving-card indicators, such as a radio magnetic indicator (RMI) or a horizontal situation indicator (HSI).The basic components of a gyrosyn compass are a remote compass transmitter, a gyroscope, an erection mechanism, an amplifier, and a heading indicator. The remote compass transmitter senses the earth’s magnetic field and is located generally in the fin or an area where there is least magnetic interference. This sensing element is pendulously suspended within a sealed bowl and maintains a horizontal plane within specified pitch attitude limits. There may be erroneous signals from the remote compass transmitter during large changes in heading, air speed, or pitch that result in the sensing element being displaced from the horizontal. The stability provided by the gyroscope ensures that these erroneous indications are nullified and correct indications are there once the aircraft returns to straight-and-level, unaccelerated flight. The erection mechanism keeps the gyro spin axis in a horizontal plane. The amplifier is the coordination and distribution center for all system electrical signals.
Aviation dictionary. 2014.