Aircraft Compass Navigation

What is the increment of graduation on a compass card?

30-degree increments
15-degree increments
1-degree increments
5- or 10-degree increments (correct)

What is the purpose of the lubber line in a compass?

To provide a reference point for the compass card (correct)
To indicate the direction of the wind
To adjust the magnetic inclination
To measure the dip angle

Why is the magnet system assembly mounted pendulously in a compass?

To counter the effect of dip (correct)
To align the magnet with the vertical component of the lines of force
To increase the effect of dip on the magnet
To reduce the effect of gravity on the magnet

What is the approximate dip angle in aircraft compasses between the latitudes 60° north and south?

3 degrees (C) Signup and view all the answers

Why is a magnetic compass unreliable above latitudes 60° north and south?

Due to the effect of dip on the magnet (B) Signup and view all the answers

What is the purpose of counterbalancing a compass magnet system for a region?

To ensure readability in different regions (B) Signup and view all the answers

What is the primary reason for filling compasses with a liquid?

To make them aperiodic (B) Signup and view all the answers

What is the purpose of the spider in a compass?

To act as a damping device (B) Signup and view all the answers

What is the effect of the movement of the magnet system and its spider in a compass?

It sets up small eddies which are quickly dissipated (A) Signup and view all the answers

Why is it important to check the calibration of a new compass from overseas before use on Australian aircraft?

Because the compass may not be designed for operation in southern latitudes (C) Signup and view all the answers

What is the benefit of the liquid in a compass in terms of the weight on the pivot?

It decreases the weight on the pivot (C) Signup and view all the answers

What type of liquid is commonly used in compasses?

Mineral or alcohol (A) Signup and view all the answers

What are the two distinct errors that the effect of acceleration can cause on a pendulous card?

Turning error and acceleration error (D) Signup and view all the answers

Why does the pendulous card's centre of gravity swing outward and rotate during a turn?

Due to the force of centrifugal acceleration (D) Signup and view all the answers

What happens to the magnet system of the pendulous card when it is tilted during a turn?

It is free to rotate under the influence of the vertical component of the Earth's magnetic field (B) Signup and view all the answers

In which hemispheres are the turning errors greatest when an aircraft is turning from a northerly or southerly heading?

Northern and southern hemispheres (C) Signup and view all the answers

What is the relationship between the turning errors in the southern and northern hemispheres?

They are mirror images (B) Signup and view all the answers

What is the direction of the force that causes the pendulous card's centre of gravity to swing outward and rotate during a turn?

Away from the centre of the turn (B) Signup and view all the answers

What is the primary function of the servomechanism in a compass system?

To rotate the compass card in response to heading changes (B) Signup and view all the answers

What is the purpose of the dot/cross flag in the compass system?

To monitor the compass system's synchronization with the Earth's magnetic field (D) Signup and view all the answers

What is the function of the knob on the bezel?

To allow rapid manual synchronization of the card heading to the flux valve heading (C) Signup and view all the answers

What type of format is used to present magnetic heading information?

Vertical card format (B) Signup and view all the answers

What is the purpose of the lubber line in the compass system?

To provide a visual reference for reading the aircraft's magnetic heading (B) Signup and view all the answers

What is the advantage of having a separate compass control panel in more complex systems?

It de-clutters the instrument bezel/display (A) Signup and view all the answers

What is the main cause of hard iron magnetism in an aircraft?

The alignment of the magnetism in the fuselage during construction (D) Signup and view all the answers

How does the strength of hard iron magnetism components change over time?

It may weaken over time (C) Signup and view all the answers

What is a characteristic of hard iron magnetism errors?

They are single-cycle errors (C) Signup and view all the answers

What type of metals are classified as soft iron?

Metals that are easy to magnetise and lose their magnetic state once the magnetising force is removed (C) Signup and view all the answers

What is a potential source of hard iron magnetism errors in an aircraft?

Magnets in speakers or DC motors (C) Signup and view all the answers

At how many points does the magnetic vector align with the Earth's magnetic field, resulting in no error?

Two points (C) Signup and view all the answers