Heading Indicator | Gyromagnetic Compass Flashcards
A DRC’s indications get ___ nearer to the Poles
weaker
A gyrocompass is a DGI that ___
aligns itself
In an area with ___ magnetic flux, such as the Poles, you should disable the automatic slaving and use the instrument as a DGI
weak
The gyroscope provides short term stability for the ___ reference
azimuth
The gyroscope has _ degrees of freedom, and the input axis is ___, meaning that the spin axis is ___
2 vertical horizontal
The erection mechanism keeps the axis ___
horizontal
The flux valve detects the element of the ____
Earth’s mag field
The flux valve should be positioned ___
as far as possible from magnetic influence
If the flux valve ceases to provide reliable information, it may generate a red ___ message on the ___
HDG HDI
The flux valve will provide a torque on the ___ axis
sensitive
The flux valve works on the principle that You can produce your own flux which changes with _, then measure that and interpret the resulting ___
H, voltage
The measuring of flux is done with a device which has _ transformers, at ___ degrees to each other, with a curved horn at their ends to maximise reception
3 120
_ spokes allow the flux valve’s orientation to the North
3
Flux valves are made of ___ as it loses magnetic influence once the power is gone, and can be magnetised quickly.
permalloy
Hysteresis is the property of ___
being able to lose magnetic influence once power is removed
The ___ influence is obtained when the spoke is in line with the Earth’s magnetic field, and any in between vary with the ___ of the Magnetic Heading
maximum cosine
An exciter coil is placed in the centre, and fed with ___ Hz single phase _C to allow a reversing magnetic field to be created through the primary coil around each spoke.
400 A
With the aircraft on a fixed heading, the field remains ___
constant
When the aircraft turns, the magnetic field changes and a ___ is induced in the secondary coil
current
When the AC is pumped through a flux valve, it produces a ripple at twice the frequency of the original current, producing a sinusoidal wave of ___ Hz with the amplitude in proportion with the Earth’s magnetic field, and the ___ of the magnetic heading.
800 cosine
It is suspended in a hooke’s joint to capture as much _ as possible, rather than _, which is responsible for turning errors
H z
The system ___, rather than seeks
senses
The information from the flux valve is compared to what the display says, and the results are sent to an ___ ___. The signals are passed through ___ and ___ ___, which precesses the directional gyro
error detector, amplifier, torque motor
FEAT
The current flows through the ___, which tells you that synchronisation is taking place correctly.
annunciator
