The VOR (15-05-18)

Question 1

What does VOR stand for?

Answer 1

VHR Omni-directional Range

Question 2

What frequency range does VOR operate on?

Answer 2

108 - 118MHz

Question 3

What frequency band does an ILS locator operate on?

Answer 3

108.1 - 111.95MHz

Question 4

How do you differentiate between ILS locator frequency bands and VOR frequency bands between 108 - 112MHz?

Answer 4

if the first digit after the decimal is ODD then the frequency band is for ILS.

Question 5

What can the combination of a VOR and a DME give you?

Answer 5

A bearing and range fix

Question 6

What are the properties of the reference phase of a VOR?

Answer 6

FM and 30MHz

omnidirectional polar diagram

Question 7

What are the properties of the variphase of a VOR?

Answer 7

AM at 30MHz

Rotating limacon polar diagram

rotates clockwise when seen from above.

Question 8

What is the principle of operation of a VOR?

Answer 8

Magnetic bearing by phase comparison producing a radial.

Variation is applied at the VOR

P prop R^2

Question 9

What are the different types of VOR?

Answer 9

Conventional VOR (CVOR)

Broadcast VOR (BVOR)

Doppler VOR (DVOR)

Terminal VOR (TVOR)

Test VOR (VOT)

Tactical air navigation VOR (VORTAC)

Question 10

What is the major problem with CVOR and how can it be fixed?

Answer 10

Siting error (multipath error) leading to the need for it to be fixed on flat open terrain.

The cure for this is the DVOR

Question 11

What is the difference in principle operation between a CVOR and a DVOR?

Answer 11

For DVOR there is no turning piece so the phase difference is created electronically and turns anticlockwise when viewed from above

Question 12

What are the properties of the Omni Bearing Indicator (OBI)?

Answer 12

Full scale deflection in VOR mode is 10deg(or more)

2 deg per dot in a 5 dot system

5 deg per dot in 2 dot system

THEY HAVE NO KNOWLEDGE OF HEADING

The TO/FROM flag will flip when flying overhead.

Question 13

What is the 1/60 rule?

Answer 13

RA = 60D

R is adjacent

A is angle between adjacent and hypotenuse

D is opposite

Question 14

What are the properties of a Radio Magnetic Indicator (RMI)?

Answer 14

Compass card rotates

Can show both VOR and ADF

Head shows QDM

Tail shows QDR

Heading is always at the top

Question 15

What are the properties of a Horizontal Situation Indicator (HSI)?

Answer 15

Heading is taken into account

The TO/FROM flag does not take the heading into account.

Question 16

What are the dimensions of the cone of confusion for a VOR?

Answer 16

50deg

Question 17

When does the TO/FROM flag flip with a VOR?

Answer 17

When you exit the cone of confusion

Question 18

What are the effects of deviation on VOR?

Answer 18

It does not affect it as it provides a mag bearing

Question 19

When an RMI compass card is stuck, how will displayed sense and QDM be affected for ADFs and VORs?

Answer 19

ADF will show correct sense but wrong QDM

VOR will show correct QDM but incorrect sense

Question 20

What errors are associated with a VORs?

Answer 20

Propagation error

Multipath error

Station interference

Super refraction

Sub refraction

Sporadic E

Question 21

What is max theoretical range for a VOR?

Answer 21

MTR = 1.23 x (root(HtTx) + root(HtRx))

in nm

Question 22

What is the accuracy of the VOR system as a whole and its sub parts?

Answer 22

Ground equipment: +/- 1deg

Airborne equipment: +/- 3deg

Unknown withing DOC +/- 1deg

Total system error +/- 5deg

Question 23

When will the ground equipment monitoring system transfer automaticaly from the master to stand by beacon?

Answer 23

When there is a change of bearing in excess of 1 deg at station

When there is a reduction in either or both of the reference and directional signal by more than 15% or carrier wave by more than 15%

When the monitor itself fails.

Question 24

What is the Designated Operational Coverage (DOC)?

Answer 24

Essentially promulgated range but for a VOR

is valid for both day and night

can be sectorised.