Gyro-Magnetic Compass Flashcards
The gyro-magnetic compass is known by several names. It can be referred to as the:
- Gyro-magnetic Compass.
- Remote Indicating Compass.
- Slaved Gyro Compass.
Use FEAT to remember the order:
F – FLUX = sends signal to “ERROR” detector
E – ERROR detector (selsyn) = sends signal to “AMPLIFIER”
A – AMPLIFIER = sends signal to “TORQUE” motor or gyro precession coil
T – TORQUE motor
Use FEAT to remember the order:
F – FLUX = sends signal to “ERROR” detector
E – ERROR detector (selsyn) = sends signal to “AMPLIFIER”
A – AMPLIFIER = sends signal to “TORQUE” motor or gyro precession coil
T – TORQUE motor
The use of the gyro gives stability and rigidity to the compass headings because the precession motor applies
corrections to the drive shaft at the rate of approximately only _° per minute.
3
When the gyro is started up on initial switch-on, the alignment it adopts is random and is
unlikely to be in synchronization with the earth’s magnetic field. Therefore an error signal is
detected at the gyro drive shaft. The problem is that the precession motor’s normal correction
rate is only 3° per minute and if the gyro happened to be 90° out, it would take 30 minutes to
synchronize, which is obviously unacceptable.
The solution is to have a -
which can either be a mechanical clutch
operated by the pilot (as in the DGI) or, in later compasses, a high gain mode for the precession
amplifier (similar in principle to rapid erection in the electric artificial horizon). This is operated
by a 2 position switch, spring-loaded to the normal position, which has to be held against the
spring for rapid alignment. Operation of this switch increases the precession motor’s correction
rate so that synchronization takes only a few seconds.
rapid synchronization facility
The detector unit is positioned in a part of the aircraft least affected by on-board electrical
fields (usually the wing tip or tail fin, where any aircraft generated magnetic disturbances are
at a minimum). Its function is to sense the direction of the earth’s magnetic field. It contains
a pendulous magnetic detecting element mounted on a Hooke’s Joint which enables the
detector to swing within limits of __° about the pitch and roll axes, but allows no _____
in ______. The unit itself is contained in a sealed case partially filled with oil to dampen any
oscillations created during flight.
The detector unit is positioned in a part of the aircraft least affected by on-board electrical
fields (usually the wing tip or tail fin, where any aircraft generated magnetic disturbances are
at a minimum). Its function is to sense the direction of the earth’s magnetic field. It contains
a pendulous magnetic detecting element mounted on a Hooke’s Joint which enables the
detector to swing within limits of 25° about the pitch and roll axes, but allows no rotation
in azimuth. The unit itself is contained in a sealed case partially filled with oil to dampen any
oscillations created during flight.
A gyro-magnetic compass gyro is kept in -
Via a -
the horizontal
Erection system
