Heading Indicator | Gyromagnetic Compass

Question 1

A DRC’s indications get ___ nearer to the Poles

Answer 1

weaker

Question 2

A gyrocompass is a DGI that ___

Answer 2

aligns itself

Question 3

In an area with ___ magnetic flux, such as the Poles, you should disable the automatic slaving and use the instrument as a DGI

Answer 3

weak

Question 4

The gyroscope provides short term stability for the ___ reference

Answer 4

azimuth

Question 5

The gyroscope has _ degrees of freedom, and the input axis is ___, meaning that the spin axis is ___

Answer 5

2 vertical horizontal

Question 6

The erection mechanism keeps the axis ___

Answer 6

horizontal

Question 7

The flux valve detects the element of the ____

Answer 7

Earth’s mag field

Question 8

The flux valve should be positioned ___

Answer 8

as far as possible from magnetic influence

Question 9

If the flux valve ceases to provide reliable information, it may generate a red ___ message on the ___

Answer 9

HDG HDI

Question 10

The flux valve will provide a torque on the ___ axis

Answer 10

sensitive

Question 11

The flux valve works on the principle that You can produce your own flux which changes with _, then measure that and interpret the resulting ___

Answer 11

H, voltage

Question 12

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

Answer 12

3 120

Question 13

_ spokes allow the flux valve’s orientation to the North

Answer 13

3

Question 14

Flux valves are made of ___ as it loses magnetic influence once the power is gone, and can be magnetised quickly.

Answer 14

permalloy

Question 15

Hysteresis is the property of ___

Answer 15

being able to lose magnetic influence once power is removed

Question 16

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

Answer 16

maximum cosine

Question 17

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.

Answer 17

400 A

Question 18

With the aircraft on a fixed heading, the field remains ___

Answer 18

constant

Question 19

When the aircraft turns, the magnetic field changes and a ___ is induced in the secondary coil

Answer 19

current

Question 20

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.

Answer 20

800 cosine

Question 21

It is suspended in a hooke’s joint to capture as much _ as possible, rather than _, which is responsible for turning errors

Answer 21

H z

Question 22

The system ___, rather than seeks

Answer 22

senses

Question 23

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

Answer 23

error detector, amplifier, torque motor

FEAT

Question 24

The current flows through the ___, which tells you that synchronisation is taking place correctly.

Answer 24

annunciator

Question 25

The synchronisation knob is there for manual correction of gross ___ in level flight; it has the same function as the caging knob

Answer 25

topple

Question 26

___ error arises from banking, and disappear once the turn is complete

Answer 26

gimballing

Question 27

___ accelerations which make the flux valve tilt can cause heading errors.

Answer 27

Horizontal

Question 28

A ___ rate of turn in a ___ aircraft would show the greatest heading error

Answer 28

high, fast

Question 29

Slow prolonged turns at high speeds generate the ___ errors

Answer 29

greatest

Question 30

Coriolis error can (not) be calculated and compensated for

Answer 30

it can

Question 31

Whenever you fly a rhumb line, the aircraft must turn to maintain a constant track, which is an acceleration that displaces the detector from the ___ plane. This is ___ Error

Answer 31

horizontal, Vehicle Movement

Question 32

Vibrations can result in heading ____

Answer 32

oscillation

Question 33

The ___ is the mechanism by which information is sent to the crew stations and instruments

Answer 33

Transmission Display System

Question 34

The torque motor makes the gyro precess in azimuth at about _ degrees per minute

Answer 34

2

Question 35

A ___ shows when it’s being precessed in one direction, a ___ in another

Answer 35

dot, cross

Question 36

In normal ops, the dot and cross should oscillate ___

Answer 36

quickly

Question 37

The most significant errors are ___

Answer 37

• Apparent and real wnder
• Gimballing
• Mech defects
• Low rotor speed

Question 38

Outline how the error detector works

Answer 38

It compares the data from the flux valve with the indication of the gyromagnetic compass.