NDB Flashcards
Where can NDB information be displayed?
on the bearing pointer
what is NDB range dependant on?
transmitter power
what causes dip?
the ADF antenna banks with the aircraft. The ADF needle dips towards the dipped wing.
when are the only times we assess the dip?
with wings level or in a rate 1 turn
what is rate 1 turn dip in:
- DA42
- FNPT2
15 degrees
10 degrees
considering 10 degrees of dip, where should the bearing pointer be with 60 degrees to go until the command heading?
on the inbound track (10 degrees from the inbound track without dip)
considering 10 degrees of dip, where should the bearing pointer be with 30 degrees to go until the command heading?
5 degrees past the inbound track (5 degrees from the inbound track without dip)
where should the bearing pointer be just before rolling out?
10 degrees past the inbound track
in an NDB hold how do we correct undershoot?
fly straight until the correct 10 degrees to go point is reached and then continue the turn. reassess against 30 degrees
when is quadrantal error at a maximum?
when the station is at 45 degrees from the nose or tail of the aircraft
how do we minimise quadrantal error?
avoid using 45 degree intercepts
what is mountain/terrain effect?
when the ADF needle wanders between the actual NDB signal and the signal reflected off terrain.
how can we compensate for mountain/terrain effect?
fly at a higher altitude and/or crosscheck the NDB information with other navigation sources
what causes night effect?
the ionosphere changes at night meaning the waves reflect off the earth.
where is night effect at a minimum?
inside the ‘skip distance’ of the NDB at short range
when is night effect likely to be at its worst?
during sunrise and sunset when the ionosphere is changing
what is coastal refraction?
when the wave bends due to passing over a change in surface such as a coastline. crossing a coastline the wave will bend towards the land
how do we mitigate coastal effect?
anticipate needing to move further inland when crossing a coastline in order to maintain track
when will there be no coastal refraction?
when the aircraft flys at 90 degrees to the coastline
what does the NDB ANT mode do?
disables the sense antenna and allows clearer audio for identification (will show 090R) on the bearing pointer)
what is the BFO used for?
identifying older NDB’s
how do we recognise ADF failure?
Red Cross and bearing pointer disappears
how down recognise NDB loss of signal?
bearing pointer disappearing and ‘NO DATA’ shown in the ADF box
