06 VOR

Question 1

Frequencies in use for VOR and ILS?

Answer 1

VORs transmit in the VHF frequency band, between 108.00–117.975 MHz.
Between 108.00–111.975 MHz, the instrument landing system (ILS) uses frequencies with an ODD number after the decimal point.

Question 2

VORs include?

Answer 2

• Conventional VOR (CVOR).
• Doppler VOR (DVOR).
• En-route VOR. - Use for IFR trafic along ATS routes at higher altitude.
• Terminal VOR (TVOR). - Low powered used for ILS. used as part of approach and departure procedures. Usually 108-112MHz
• Test VOR (VOT). - V low power to test AC equioment.

Question 3

CVOR

Answer 3

Clockwise 30Hz
Contains moving parts.

Question 4

DVOR

Answer 4

• 30Hz variphase trasnmitted from a number of antennas
• 30Hz refernece signal from a dipole.
• FM vari-phase signal rotates anti-clockwise at 30Hz.
• no moving parts.

Question 5

Operating principle of a VOR?

Answer 5

VORs transmit reference (FM) and variable phase navigation (AM) signals. The phase difference between the two signals determines the magnetic bearing (radial) from the VOR.

Produces a 1800rpm rotating cardiod limacon with one null representing the phase differnece.

Question 6

VOR Identification?

Answer 6

VORs are identified using a three letter Morse code and/or plain voice communications. Every 10 seconds at 1020Hz

Question 7

Ground monitoring?

Answer 7

VORs have an automatic ground monitoring station. Failure to remain within accuracy limits will remove the transmitted navigation and identification signals.

Ground transmitter error shall be within +/-2 degrees.

Question 8

When may the ground transmittor be shut down?

Answer 8

The ground transmitter error shall be within +/- 2°.

• However, the transmitter should transmit a warning to the self-monitoring control unit, and either remove the identification and navigation components from the carrier wave if:
• The bearing information transmitted by the VOR changes by > 1°
• The modulated components voltage level reduces by 15%

The following may also contribute to the accuracy at the receiver:

• Propagation error (disturbance of the signal as it travels)
• Airborne equipment error.

Question 9

ATIS frequency?

Answer 9

ATIS (automatic terminal information service) information is often transmitted on a VOR frequency.”

Question 10

Airborne equipment includes:

Answer 10

• Antenna - 1/4 wavelength horizontally polarised, often on the tailfin.
• VHF NAV receiver.
• Cockpit display indicator.

Question 11

Where can VOR info be found?

Answer 11

A Course Deviation Indicator (CDI), Horizontal Situation Indicator (HSI) and/or Radio Magnetic Indicator (RMI) (feat. moving compass card) is used to determine VOR information.

Question 12

Maximum angular displacement?

Answer 12

The angular displacement from a selected radial is read on a CDI or HSI. The maximum displacement is ±10°.

Question 13

Flags?

Answer 13

The TO/FROM flags on the CDI/HSI are used to indicate the aircraft position relative to the VOR, considering the selected radial.
An RMI is used to indicate a radial from a VOR:

Question 14

Arrow head and tail?

Answer 14

Radial FROM (QDR) – at the tail of the needle.
TO (QDM) – at the point of the needle.

Question 15

VOR uses?

Answer 15

A VOR is used for en-route navigation, procedural turns, holding patterns and instrument approach procedures, along selected radials.
VOR tracking accuracy must be within half-scale deflection (±5°), taking wind effect into account.”

Question 16

VOR Scalloping?

Answer 16

Scalloping is a fluctuation of the navigation signal and occurs when signals are reflected by terrain, buildings or vehicles.”

Scalloping is a fucntion of VHF frequencies.

Question 17

VOR/DME?

Answer 17

DME ident frequency 1350Hz, with same letters as VOR transmitted after every 3 VOR idents. Higher pitch.

Question 18

VOR/DME in terminal area?

Answer 18

In a terminal area VOR and DME trasnmitters must not be mre theen 100ft apart
All other VOR types must be within 2000ft (600m)

A DME more than 2000ft but within 6nm may be given a similar ident to VOR but last better will be a zulu.

Question 19

OBI?

Answer 19

Omni bearing indicator / CDI. Used to track radials onto and away from bearings.

Not slaved to the compass.

Max +/- 10 degrees. Each dot is 2 degrees.

Question 20

HSI

Answer 20

Compass rose with an OBI in the middle.

To/from flags do not relfect aircraft heading but instead point with respect to the beacon and the course selected to it.

Question 21

VOR cone of confusion?

Answer 21

Tan(50) for VOR
Tan(40) for NDB

Question 22

TSE?

Answer 22

VOR total system error. The accuracy of the VOR system is 5 degrees.

Question 23

In order to enter a VOR into an RNAV route should be in range when?

Answer 23

Not when entered, but should be in range when used.

Question 24

Issues with using VORs outside the desired range?

Answer 24

May lead to interfering signals from other VORs.

Question 25

established meaning?

Answer 25

Established means to be within 5º of the track. Since a full deflection on a VOR equals 10º, we can say that “When the VOR indicator is within half full-scale deflection.” is correct.