VOR Flashcards
Frequency range of VOR?
108 - 117.975 MHz
Between … and … MHz the band is shared with ILS so VOR frequencies are only allocated at … spacing, with ILS using … spacing
108
112
EVEN 100 KHz (100 KHz is 0.1 MHZ)
ODD 100 KHz
100 KHz is … MHZ
0.1
From … to …MHz the band is solely used by VOR so spacing is reduced to …
112
117.975
50 KHZ (0.05 MHz)
standard VOR consists of a cylindrical cover containing a horizontal … aerial which is spinning at … RPM
dipole
30
Slots in the VOR cylinder combined with the rotating dipole produce a … shaped polar diagram which also rotates at 30 RPM (does not have a sharp null like the NDB cardioid)
limacon
VOR variphase signal is …. modulated at …hz
amplitude
30
VOR reference signal is … modulated at …Hz
frequency
30
Most primitive VOR instrument is the …, or …
course deviation indicator (CDI
omni bearing indicator (OBI)
There is no TO/FROM flag an on RMI and the head of the needle indicates … with the tail indicating …, just as with the NDB
QDM
QDR
ICAO limits for cone of confusion are up to … degrees from the vertical
50
VOR ident is … letter morse code, at … words per second, repeating every … seconds
3
7
10
ICAO VOR accuracy?
+/- 5 degrees on 95% of occasions
VOR free from sky wave interference and coastal refraction because …
of its higher frequency and line of site transmission
Quadrantal error does not exist in VOR because
bending of the signal by aircraft structure would not affect the indicated bearing
What is scalloping aka site error?
Reflections from terrain and man-made obstructions can cause errors as two signals with different phase differences interfere. Causes needle to move rapidly from side to side and make RMI needle wobble.
Scalloping different from beam bends which are also caused by reflections from buildings but which are more predictable slight curves within the system tolerances
What is aircraft VOR accuracy?
Within total 5 degrees bearing accuracy the aircraft equipment must be accurate to 3 degrees
VOR station will be shut down if the signal strength drops by more than … or …
15%
the monitor fails
Max theoretical range of VOR formula?
see image
Doppler VOR variphase signal is … modulated
frequency
A broadcast VOR is usually a
terminal aid giving out ATIS etc. superimposed on to the carrier wave
VOR and DME using same frequency have to be within … of each other but often co-located
600m
