VOR Flight Reference

Question 1

Bank angle for a polarisation check

Answer 1

30°

(FIP24 - P20, 7.1.4)

Question 2

Profile for a polarisation check

Answer 2

Any radial (profile 21) at a distance between 10NM and 20NM

Question 3

Sine wave in the graphic

Answer 3

Check antenna coordinates in site file

Question 4

4 things to do post-calibration

Answer 4

Data files copied to server
Engineers contacted
Provisional report sent
Teams logbook completed

Question 5

Where to check a VOR IDENT

Answer 5

Every 1/4 of an orbit
Furthest point on each radial

Question 6

VOR Profiles Vertical Reference

Answer 6

Altitude

(AMSL)

Question 7

VOR Range

Answer 7

DOC found in relevant AIP

Question 8

Reference and variable modulation frequencies

Answer 8

DVOR:
Reference: 30Hz
Variable: 9960Hz

CVOR:
Reference: 9960Hz
Variable: 30Hz

Question 9

Tolerances for alignment, bends, roughness, scalloping on bearing error

(ICAO 8071)

Answer 9

Alignment: ±2°
Bends: ±3.5°
Roughness and Scalloping: ±3°

(ICAO 8071 - P71, I-2-25)

Question 10

Minimum power density for a VOR

Answer 10

-107dBW/m²

(90µV (microvolts) per metre)

(ICAO 8071 - P71, I-2-25)

Question 11

9960Hz and 30Hz mod depth tolerance

Answer 11

Nominal is 30% is for both.
- 30Hz: 25-35% (8071) / 28-32% (NATS)
- 9960Hz (without voice): 20-55% (8071) / 28.5-31.5% (NATS)

(ICAO 8071 - P71, I-2-25 / NATS VOR Requirements)

Question 12

DME range error tolerance

Answer 12

0.1NM

(CAP 670 - P371, NAV06.5) (Rounded from ICAO 8071 tolerance - P85, I-3-13)

Question 13

DME minimum power density

Answer 13

-89dBW/m²

(ICAO 8071 - P85, I-3-13)

Question 14

Piloting Accuracy Tolerances

Answer 14

Orbit (profile 22): ±25ft, 2 dots, 160kts ±30kts
Radial (profile 21): ±25ft, 1 dot, 160kts ±30kts
Approach radial (profile 21): ±25ft, 1 dot, 140kts ±20kts

(FIP24 - P17, 7.1.1) (FIP24 - P18, 7.1.2)

Question 15

VOR orbit altitude in IMC

Answer 15

1,000ft above highest obstacle within 5NM of required track. 2,000ft over mountainous terrain. Round to nearest 100ft.

(FIP24)

Question 16

Areas of an AIP including magnetic variation

Answer 16

AD 2.2 - Aerodrome geographical and administritive data
AD 2.19 - Radio navigation and landing aids
AD 2 - Any approach charts

Question 17

Low RF Level

Answer 17

Aircraft antenna
Bank angle
Terrain or obstacles affecting signal
Power corrections not being applied correctly

Question 18

Terrastar accuracy

Answer 18

No explicit requirement. If the GPS signal looks especially poor, check with a Senior FI

Recommended accuracy below 0.1m

Question 19

FM Index

Answer 19

Copy VOR data file
Drag and drop data file to extract_evs.cmd in AFIS4/AWK folder
Find and open data file excel file
Select FM index column
Average shown at bottom

Question 20

Polarisation Tolerance

Answer 20

±2°

(ICAO 8071 - P71, I-2-25)

Question 21

FM Index Tolerance

Answer 21

16 ±1

Question 22

VOR Cone of Confusion Equation

Answer 22

(height above VOR / Sin(40)) / 6076
or
(height above VOR / Cos(50)) / 6076