NDB

Question 1

Type of modulation - NDB

Answer 1

Amplitude modulated

Question 2

Freq of NDB

Answer 2

190KHz to 1750KHz

Question 3

Equipment in the a/c used for NDB

Answer 3

Loop antenna
Sense antenna
ADF receiver
An indicator

Question 4

Different ways to present NDB

Answer 4

Fixed card ADF (radio compass) 
Moving card ADF 
Radio magnetic indicator (RMI) 
Symbols on an electronic navigation display (EFIS ND) 
Radio magnetic indicator (RMI)

Question 5

Relative bearing, fixed card

Answer 5

The cardinal points do not move only the needle moves

Question 6

Relative bearing, moving card

Answer 6

Rotate heading after each turn

Gives you the bearing of the NDB in relation to your current heading

Question 7

QDM/ magnetic steer equation

Answer 7

Relative bearing + magnetic HDG = QDM

Have to convert the units into relative bearing or magnetic heading o QDM for it to work

Question 8

Tracking accuracy NDB

Answer 8

Class B - so it must be within +- 5 degrees of the desired track

Question 9

Coverage and range of the NDB

Answer 9

Limited by power and line of sight

D=1.23(square root Rx + square root Tx)

New power/old = (New range/old) squared

So if you double the range, power has to go up by 4x

Question 10

NDB transmission consists of

Answer 10

Sky waves and surface waves

Question 11

NDB range at night

Answer 11

NDB range will increase due to ionosphere becoming smaller and higher

However, the useable range will decrease due to mixing

Question 12

NDB system limitations

Answer 12

Biggest drawback is the lack of failure flags

Question 13

Different errors that effect NDB accuracy

Answer 13

Static interference 
Night effect 
Coastal refraction 
Multi path propagation 
Quadrantal error 
Bank angle error

Question 14

Static interference error NDB

Answer 14

Most significant
Can make the ADF completely unreliable

Makes the needle point at anything noisy,

Question 15

Night/ twilight effect

Answer 15

Due to the raised ionosphere
Sky and surface waves get closer together and they mix which causes fading
Reduces the operational range of the NDB

Question 16

Coastal refraction

Answer 16

As there is less friction over the sea than over the land
The signal gets bent due to the speed change
If the beacon on the coast has limited angular distance, there will be no bending

The further inland the beacon is, the stronger the bending is

Question 17

Multi path propagation

Answer 17

Could be known as mountain effect

Applies to every radio aid

Radio waves bounce off terrain/objects and pick up the reflected signal instead of the actual

Question 18

Bank angle error

Answer 18

Caused by the change in voltages through the loop antenna

Makes the needle point into the turn

Question 19

Quadrantal errors

Answer 19

Caused by the a/c structure bending the wave as it reaches the a/c

Has a insignificant effect on the cardinal points

The most significant if the ave is coming from midway between each cardinal point