NDB/ADF Flashcards
Ground directof finding
antenna adcock or doppler VDF normal class B source of error equpment error propagation error site error
FACTOR AFFECTING RANGE
power - sensitivity reciever - udct propagation
NDB
NON DIRECTIONAL BEARING
ground base trasmitter antenna or locator
use to en route navigation or homing and let down
IDENT 2/3 morse letter
in the published range no interference from other NDB(DOC Designated Operational Coverage)
NDB frequency
Frequency 190 KHz to 17950 KHz Frequency band LF/MF Propagation surface wave type of emission N0NA1A N0NA2A
NDB range
Power 25 watts 25 NM
Range 10 KW to 500 NM
surface wave range proportional to 1/f
terrain surface wave attenuation mx range over sea
NDB interference
2 NDB with the same frequency
to use only in the DOC
max error +-5 during the day
Locator
10 to 25 NM usually A2A
approach aid, often located with ILS marker
ident 10 second
Homing/Holding
up to 50 NM
a/p vicinity
A2A ident 10 sec
En rooute
100 to 500 nm
airways or island
A2A or A1A ident 1 min
ADF
AUTOMATIC DIRECTION FINDING
ADF antenna
loop antenna
sense antenna
they create a cardiod that can permit to feel the direction of the NDB
RBI
relative bearing indicator Fixed will require use of mental maths to obtain QDM.
Moving Compass Card) will
show QDM when current MH is set on the display
RMI
Relative magnetic indicator
will always show QDM as it’s linked to the compass
ADF indications
fly the a/c on any heading to keep the needle pointed to 000° R
Relative bearing
RB= N - HDG + QDM
ADF limitation
Lack of warning device static night effect costal refraction quadrantal error(correct) attitude error(DIP)
