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Flashcards in VOR Deck (22)
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1

Frequency range of VOR?

108 - 117.975 MHz

2

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

3

100 KHz is ... MHZ

0.1

4

From ... to ...MHz the band is solely used by VOR so spacing is reduced to ...

112

117.975

50 KHZ (0.05 MHz)

5

standard VOR consists of a cylindrical cover containing a horizontal ... aerial which is spinning at ... RPM

dipole

30

6

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

7

VOR variphase signal is .... modulated at ...hz

amplitude

30

8

VOR reference signal is ... modulated at ...Hz

frequency

30

9

Most primitive VOR instrument is the ..., or ...

course deviation indicator (CDI

omni bearing indicator (OBI)

10

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

11

ICAO limits for cone of confusion are up to ... degrees from the vertical

50

12

VOR ident is ... letter morse code, at ... words per second, repeating every ... seconds

3

7

10

13

ICAO VOR accuracy?

+/- 5 degrees on 95% of occasions

14

VOR free from sky wave interference and coastal refraction because ...

of its higher frequency and line of site transmission

15

Quadrantal error does not exist in VOR because 

bending of the signal by aircraft structure would not affect the indicated bearing

16

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

17

What is aircraft VOR accuracy?

Within total 5 degrees bearing accuracy the aircraft equipment must be accurate to 3 degrees

18

VOR station will be shut down if the signal strength drops by more than ... or ...

15%

the monitor fails

19

Max theoretical range of VOR formula?

see image

20

Doppler VOR variphase signal is ... modulated

frequency

21

A broadcast VOR is usually a 

terminal aid giving out ATIS etc. superimposed on to the carrier wave

22

VOR and DME using same frequency have to be within ... of each other but often co-located

600m