VORs

Question 1

VHF Frequency Range

Answer 1

108 MHz to 117.95MHz

Question 2

Conventional VOR

Answer 2

Reference phase is FM
Variable phase is AM
Clockwise movement
Strongest when ac directly pointing at beacon
Rotating antenna 30 times per second

Question 3

Doppler VOR

Answer 3

Reference phase AM
Variable phase FM
Anti-clockwise
Uses electronic sweeping

Question 4

Principles of operation of a VOR

Answer 4

Bearing by phase comparison
Two signal phases
90 degrees - east
180 degrees - south
Etc

Question 5

Doppler advantages of a conventional VOR

Answer 5

More accurate
Less susceptible to siting errors

Question 6

VOR frequency band

Answer 6

112.000MHz to 117.95MHz

Think odd numbers at the end

Question 7

ILS Frequency Band

Answer 7

108.10MHz to 111.95MHz
Odd numbers below VORs 112.000MHZ

Question 8

Terminal VOR frequency band

Answer 8

108MHz to 111.80MHz
Even numbers below VOR - odd numbers in same range are ILS
50KHz separation

Question 9

Flight accuracy for a VOR

Answer 9

Must be kept within half of full scale deflection of required track

Question 10

VOR ground monitoring system - limits and operation

Answer 10

Keep within 1 degree accuracy/loss of strength signal 15%

Remove ident/nav components or shut down transmitter

Question 11

VOR errors

Answer 11

Bending - building etc/documented
Scalloping - building/vehicles/refraction - slow oscillation of bearing
Cone of confusion - 35 degrees either side vertically

Question 12

Scalloping

Answer 12

Due to reflection radials bent leading to fluctuating indications
VOR oscillates
Must be less than +- 2 degrees

Question 13

Cone of confusion

Answer 13

No single vertically above
Cannot be no less than 40 degrees above the plane of the VOR

Tan (40) x height nm x 2

Question 14

VOR are identified by

Answer 14

3 letter Morse code and or plain voice communications

Question 15

ATIS and VORs…

Answer 15

ATIS info is often transmitted on VOR frequency’s

Question 16

Doppler VOR Range

Answer 16

200NM - en route IFR traffic

Question 17

VOR/DME is a

Answer 17

Rho - theta

Question 18

Intercepting a radial flight director provides

Answer 18

Optimum bank angle to reach radial

Question 19

DME interrogator uses irregular transmission sequence because

Answer 19

Able to distinguish between his own reply pulse pairs and the reply pulse pairs of the other aircraft

Jittery Frequency

Question 20

TVOR

Answer 20

A VOR station with a shorter range used as part of the approach and departure structure of aerodrome

Question 21

DME receiver can distinguish between other aircraft’s due to

Answer 21

Unique pulse pairs

Question 22

DME receiver can distinguish between itself and the reply because

Answer 22

Frequency transmitted +- 63MHz

Question 23

TVOR Frequency Band

Answer 23

108MHz to 111.80MHz

Question 24

AC on different radials at equal distance from a VOR - Reference vs Variable Signal

Answer 24

Equal reference signal (same DME distance around VOR)
Unequal variable signals (different radials as antenna moves)

Question 25

A radial is

Answer 25

A magnetic bearing outbound from a station called the QDR.
Travel the shortest routes around earth (great circles)

Question 26

Total system error using a VOR

Answer 26

5%