VOR/DME

Question 1

VOR

Answer 1

VHF Omni-Directional Radio-Range

Question 2

Frequencies used by VOR?

Answer 2

112-118MHz

Question 3

Elements of a VOR?

Answer 3

1. Transmits 2 signals
   - One non-directional reference signal
   - One whose phase relationship to the reference signal varies with bearing from the VOR
2. VOR operates in the VHF frequency band and can operate with or without a DME.
3. Used for Navigation, Holding, & Instrument Approaches
   - Aircraft may track TO or FROM a VOR
   - Station passage is a ‘positive fix’
   - Radials only ‘radiate’ out from a VOR.

Question 4

When the VOR and DME are located together or “Collocated” how is this depicted on charts?

Answer 4

With the brace symbol “}”.

Question 5

Types of errors affecting VOR?

Answer 5

• Ground Station Error
• Site Effect Error
• Terrain Error
• Vertical Polarisation
• Airborne Equipment Error
• Aggregate Error

Question 6

Explain a VOR Ground Station Error.

Answer 6

This error is associated with the transmitter, aerial and power supply that is with the actual ground equipment. ± 2º

Question 7

Explain a VOR Site Effect Error.

Answer 7

Site effects which are due to topographical features near the ground station. ± 3º

Question 8

Explain a VOR Terrain Error

Answer 8

Terrain effects caused by the VOR radials being distorted by signals reflected from rough terrain.

Question 9

Explain VOR Vertical Polarisation

Answer 9

Detected in manoeuvres which tilt the aircraft aerial

Question 10

Explain a VOR Airborne Equipment Error

Answer 10

The error attributable to the various components of the VOR equipment in the aircraft. ± 2º

Question 11

Explain the VOR Aggregate Error

Answer 11

The algebraic sum of all the errors mentioned.

Usually less than ± 5º

Question 12

TACAN

Answer 12

Tactical Air Navigation

Question 13

What is TACAN?

Answer 13

The military equivalent of a VOR/DME installation, which operates in UHF.

Question 14

Difference between VOR and TACAN?

Answer 14

TACAN is always associated with DME.

Question 15

Which component(s) of a TACAN can civilian aircraft use?

Answer 15

DME only.

Question 16

DME

Answer 16

Distance Measuring Equipment

Question 17

Elements of DME

Answer 17

• DME provides a direct distance between an aircraft and the beacon being used.
• DME will always display the distance (in NM) from the aircraft to the beacon (slant range)
• In aircraft with EFIS the DME is integrated and has few controls
• In other aircraft it is a simple display

Question 18

What is a positive fix determined by?

Answer 18

1. The passage of the aircraft over an NDB, VOR, TACAN, marker beacon or DME site
2. The intersection of two or more position lines which intersect with angles of not less than 45 degrees and which are obtained from NDB, VOR, localisers or DME in any combination. For the purpose of this paragraph, a position line must be within the rated coverage of the aid with the exception that if a fix is determined entirely by position lines from NDB, the position lines must be within a range of 30NM from each of the NDB or;
3. GNSS meeting the equipment requirements of GEN 1.5 Section 2.