Compass

Question 1

Earth’s magnetic flux is made up of two components

Answer 1

-H component parallel to earth

-Z component perpendicular to Earth

Question 2

Earth’s lines of magnetic flux become inclined to the surface of the Earth this is know as

Answer 2

Dip

Question 3

Dip is compensated by

Answer 3

Compass having a high pivot point and low Centre of gravity

Question 4

Acceleration error in compass is caused by

Answer 4

-Pivot point and centre of gravity of the compass being offset

-The compass turns around the pivot point abut any acceleration acts through the centre of gravity

Question 5

Turning error is caused by

Answer 5

Z component acting inline withe the plane of rotation of the compass

Magnified by the offset centre of gravity and pivot point

Question 6

Deviation is

Answer 6

A/C own magnetic field interferring with the Compass

Question 7

Deviation card is

Answer 7

Compass swing in aircraft

Any residual deviation can be minimised using small compensator magnets on compass

Question 8

Flux valve in a RMI is fixed in

Answer 8

azimuth but

pendulously suspended in damping fluid to allow it to remain horizontal

Question 9

Flux valve sends info to DGU via

Answer 9

Sychro system

Question 10

DGU stands for

Answer 10

Directional gyro uni

Question 11

RMI function

Answer 11

give direction to magnetic north

similar to DI without the need to sync

Question 12

RMI minimise acceleration error by

Answer 12

DGU having a slow slaving rate

Gyroscopic rigidity of the DGU

Question 13

Slaving rate of DGU to flux vlave is approx

Answer 13

1-2 degrees per minute

Question 14

Turning error in RMI is largely eliminated by

Answer 14

flux vlave remaining the horizontal plane when aircraft rolls

Question 15

QDR is

Answer 15

magnetic bearing FROM a station