When would VDF be used for a position fix?

When an aircraft declares an emergency on any frequency

When first talking to an FIR on crossing an international boundary
C. When joining controlled airspace from uncontrolled airspace
d When declaring an emergency on 121.500 MHZ
2 What equipment does an aircraft need when carrying out a VDF let-down?
a. VHF radio
b. VOR
C. VOR/DME
d. None

3. Which of the following is an advantage of a VDF let-down?

No equipment required in the aircraft
b No special equipment required in the aircraft or on the ground
C. Only a VHF radio is needed in the aircraft
d. It is pilot interpreted, so ATC is not required
4 What is the maximum range at which a VDF station at 325 ft can provide a service to
an aircraft at FLO80?

d. 134 NM
b 107 NM
C. 91 NM
d. 114 NM

5. Which of the following statements regarding VHF direction finding (VDF) is most
accurate?

It is simple and only requires a VHF radio on the ground

b It is simple and requires a VHF radio and DF equipment in the aircraft
C. It is simple requiring only VHF radios on the ground and in the aircraft
d. It uses line of sight propagation
6. What is the wavelength corresponding to a frequency of 375 kHz?
8 m
b. 80 m
C. 800 m
d. 8000 m

7. An NDB transmits a signal pattern which is:

a 30 Hz polar diagram
b. omni-directional
C. a bi-lobal pattern
d. a beam rotating at 30 Hz
8. The accuracy of ADF within the DOC by day is:
a
+/-1°
C.
+/-2°
+/-5°
d. +/- 10°
9. Given that the compass heading is 270°, the deviation is 2°W, the variation is 30°E
and the relative bearing of a beacon is 316°, determine the QDR:
a. 044
b 048
C. 074
d. 224

10. Two NDBs, one 20 NM from the coast and the other 50 NM further inland. Assuming
coastalerror is the same for each, from which NDB will an aircraft flying over the sea
receive the greatest error?
a. The NDB at 20 NM
b. The NDB at 50 NM
C. Same when the relative bering is 090/270
d. Same when the relative bearing is 180/360
11. Which of the following is likely to have the greatest effect on the accuracy of ADF
bearings?
a. Interference from other NDBS particularly by day
Interference between aircraft aerials
C. Interference from other NDBS, particularly at night
d. Frequency drift at the ground station
12. Which of the following are all errors associated with ADF?

a. Selective availability, coastal refraction, night effect

b Night effect, quadrantal error, lane slip
Mountain effect, station interference, static interference
d. Selective availability, coastal refraction, quadrantal error
13. What action must be taken to receive a bearing from an ADF?
a. BFO on
b. Select the loop position
C. Both the loop and sense aerials must receive the signal
d. Select the LOOP position
14. When is coastal error at its worst for an aircraft at low level?

d. Beacon inland at an acute angle to the coast

b Beacon inland at 90° to the coast
C. Beacon close to the coast at an acute angle to the coast
d. Beacon close to the coast at 90° to the coast
15. Aradio beacon hasa range of 10 NM. By what factorshould the power be increased
to achieve a range of 20 NM?
a. 16
2
C. 4
d. 8

16. Which of the following is the most significant error in ADF?

a. Quadrantal error
b. Coastal refraction
C. Precipitation static
Static from Cb

17. Which of the following may cause inaccuracies in ADF bearings?

a. Static interference, height effect, lack of failure warning
b. Station interference, mountain effect, selective availability
C. Coastal refraction, slant range, night effect
d. Lack of failure warning, station interference, static interference

18. The allocated frequency coverage of NDBS is:

a. 250 - 450 kHz
190- 1750 kHz
108- 117.95 MHz
d. 200 - 500 kHz

19. The principle used to measure VOR bearings is:

a. phase comparison
switched cardioids
C. difference in depth of modulation
d. pulse technique
20. When converting VOR and ADF bearings to true, the variation at the .... should be
used for VOR and at the ..... for ADF.

a. aircraft aircraft
b. aircraft station
C. station aircraft
d. station station

21. An aircraft flies from a VOR at 61 N O13W to 58N 013W. The variation at the beacon
is 13W and the variation at the aircraft is 5W. What radial is the aircraft on?

a. 013
b. 005
C. 193
d. 187
22. In a conventional vOR the reference signal and the variable signal have a 30 Hz
modulation. The variable signal modulation is produced by:
adding 30 Hz to the transmitted signal
b a 30 Hz rotation producing a 30 Hz modulation
C. varying the amplitude up and down at +/-30 Hz
d. using Doppler techniques to produce a 30 Hz amplitude modulation
23 If the VOR accuracy has a limit of 1.0°, what is the maximum cross-track error at 200
NM?

3.0 NM
b 2.5 NM
C. 2.0 NM
d 3.5 NM

24. What is the maximum distance apart a VOR and TACAN can be located and have the
same identification?

2000 m
b 60 m
C 600 m
d. 6 m

25. What is the maximum distance between VOR beacons designating the centre line of
an airway (10 NM wide), if the expected VOR bearing error is 5.5°?
a 120 NM
b. 109 NM
C. 60 NM
d. 54 NM

26. In a certain VORTAC installation the VOR is coding STN and the DME is coding STZ.
This means that the distance between the two beacons is in excess of:

a. 600 m
b 100 m
C. 2000 m
d 300 m

27 Using a 5 dot CDI, how many dots would show for an aircraft on the edge of an
airway at 100 NM from the VÔR beacon?
a. 5
b 2.5
C. 1.5
d. 3

28. The maximum range an aircraft at FL370 can receive transmissions from a VOR/DME
at 800 ft is:

a. 275 NM
b 200 NM
C. 243 NM
d. 220 NM
29. When tracking a VOR radial inbound the aircraft vwould fly:
a constant track
b. a great circle track
C. a rhumb line track
d. a constant heading
30. Which of the following is a valid frequency (MHz) for a VOR?
107.75
b 109.90
C. 118.35
d. 112.20

31. Using a VOR beyond the limits of the DOC may result in:
loss of signal due to line of sight limitations
b interference from other VORs operating on the same frequency
C. sky wave contamination of the VOR signal
d. scalloping errors
32. An aircraft is flyingaheading of 090° along the equator, homing to a VOR. If variation
at the aircraft is 10°E and 15°E at the VOR, what is the inbound radial?
a 075
b 105
C. 255
d 285

33. When identifying a co-located VOR/DME the following signals are heard in the
Morse code every 30 seconds:
4 identifications in the same tone
b. 4 identifications with the DME at a higher tone
C. 4 identifications with the DME at a lower tone
d. no DME identification, but if the VOR identification is present and a range is
indicated then this shows that both are serviceable

34 What is the maximum range a transmission from a VOR beacon at 169 ft can be
received by an aircraft at FLO12?
a. 60 NM
b. 80 NM
C. 120 NM
d. 220 NM

35 An aircraft is tracking inbound to a VOR beacon on the 105 radial. The setting the
pilot should put on the OBS and the CDI indications are:
a. 285, TO
b 105, TO
285, FROM
105, FROM
36. When tracking the 090 radial outbound from a VOR, the track flown is:
a straight line
b. a rhumb line
a great circle
d. a constant true heading
37. The frequency band of VOR is:
a. VHF
b UHF
HF
d. LF & MF

38. On which radial from a VOR at 61 NO25E (VAR 13°E) is an aircraft at 59NO25E (VAR
20°E)?
160
b 347
C. 193
d. 167

39. What is the minimum height an aircraft must be to receive signals from a VOR at 196
ft AMSL at a range of 175 NM?
a 26 000 ft
b 16000 ft
C. 24 000 ft
d. 20000 ft

40. For a conventional VOR a phase difference of 090° would be achieved by flying
.... from the beacon:

a west
b north
C. east
d. south

41. At a range of 200 NM froma VOR, if there is an error of 1°, howfar off the centre line
is the aircraft?

a 3.5 NM
b 1.75 NM
C 7 NM
d. 1NM
42. The quoted accuracy of VOR is valid:
a. at all times
b by day only
C. at all times except night
d at all times except dawn and dusk
43. Which of the following provides distance information?
a DME
b. VOR
ADF
d. VDF

44. Which of the following would give the best indication of speed?
a. AVOR on the flight plan route
b. A VOR Off the flight plan route
A DME on the flight plan route
d. A DME off the flight plan route
45. What happens when a DME in the search mode fails to achieve lock-on?
a. It stays in the search mode, but reduces to 60 pulse pairs per second (ppps)
after 100 seconds
b It stays in the search mode, but reduces to 60 ppps after 15000 pulse pairs
It stays in the search mode at 150 ppps
It alternates between search and memory modes every 10 seconds
46. The most accurate measurement of speed by DME for an aircraft at 30 000 ft will be
when the aircraft is:

a. tracking towards the beacon at 10 NM

b. overhead the beacon
C. tracking away from the beacon at 100 NM
d. passing abeam the beacon at 5 NM
47. A DME beacon will become saturated when more than about ......... aircraft are
interrogating the transponder.
a. 10
b. 50
C. 100
d. 200

48. A typical DME frequency is:

a 1000 MHz
b 1300 MHz
C. 1000 kHz
d. 1575 MHz

49. The DME in an aircraft, cruising at FL210, fails to achieve lock-on a DME at MSL ata
range of 210 NM. The reason for this is:
the beacon is saturated
b. the aircraft is beyond the maximum usable range for DME
the aircraft is beyond line of sight range
the aircraft signal is too weak at that range to trigger a response
50. The aircraft DME receiver accepts replies to its own transmissions but rejects replies
to other aircraft transmissions because:

a. the PRF of the interrogations is unique to each aircraft

b the pulse pairs from each aircraft have a unique amplitude modulation
C. the interrogation frequencies are 63 MHz different for each aircraft
the interrogation and reply frequencies are separated by 63 MHz
51. When an aircraft at FL360 is directly above a DME, at mean sea level, the range
displayed will be:
a. 6 NM
b. 9 NM
C. 0
d. 12 NM

52. A DME frequency could be:

a 10 MHz
b. 100 MHz
C. 1000 MHz
d. 10000 MHz

53. An aircraft at FL360 is 10 NM plan range from a DME. The DME reading in the aircraft
will be:

8 NM
b 11.7 NM
10 NM
d. 13.6 NM

54. A DME transceiver does not lock onto its own reflections because:

a. the PRF of the pulse pairs is jittered

b it uses MTI
C. the interrogation and reply frequencies differ
d. the reflections will all fall within the flyback period
55. What information does military TACAN provide for civil aviation users?
Magnetic bearing
DME
C. Nothing
d. DME and magnetic bearing
56. The DME in an aircraft flying at FL430 shows a range of 15 NM from a beacon at an
elevation of 167 ft. The plan range is:
13.5 NM
b. 16.5 NM
C. 15 NM
d. 17.6 NM
57. What are the DME frequencies?
1030 & 1090 MHz
b 1030 - 1090 MHz
960 &1215 MHz
d. 960 - 1215 MHz

58. The time from the transmission of the interrogation pulse to the receipt of the reply
from the DME ground station is 2000 microseconds (ignore the delay at the DME).
The slant range is:
330 NM
b 185 NM
c. 165 NM
d. 370 NM

59. The DME counters are rotating continuously. This indicates that:
the DME is unserviceable
b the DME is trying to lock onto range
the DME is trying to lock onto frequency
d. the DME is receiving no response from the ground station
60. On a DME presentation the counters are continuously rotating. This indicates:
a. the DME is in the search mode
b. the DME is unserviceable
the DME is receiving no response from the transponder
d. The transponder is unserviceable
61. An aircraft at FL200 is 220 NM from a DME at MSL. The aircraft equipment fails to
lock on to the DME. This is because:

DME 0s limited to 200 NM

b the aircraft is too high to receive the signal
C. the aircraft is too low to receive the signal
d. the beacon is saturated

62. On an ILS approach you receive more of the 90 Hz modulation than the 150 Hz
modulation. The action you should take is:
a fly left and up
b fly left and down
C. ftly right and up
d fly right and down
63. The errors of an ILS localizer (LLZ) beam are due to:
a. emission side lobes
b ground reflections
spurious signals from objects near the runway
d interference from other systems operating on the same frequency
64. The amplitude modulation of the ILS outer marker is . and it illuminates the
.light in the cockpit.
400 Hz blue
b. 1300 Hz amber
C. 400 Hz amber
d. 1300 Hz blue

65. The principle of operation of the ILS localizer transmitter is that it transmits two
overlapping lobes on:
a. different frequencies with different phases
b the same frequency with different phases
C. the same frequency with different amplitude modulations
d. different frequencies with different amplitude modulations
66. The ILS glide slope transmitter generates false glide paths because of:
a. ground returns from the vicinity of the transmitter
back scattering of the signals
C. multiple lobes in the radiation pattern
reflections from obstacles in the vicinity of the transmitter
67. A category ll ILS system provides accurate guidance down to:
a the surface of the runway
less than 50 ft
less than 100 ft
less than 200 ft

68. A HSIcompass rose is stuck on 200 . When the aircraft is lined up on the centre line
of the ILS localizer for runway 25, the localizer needle will be:
a. left of the centre
b centred
C. right of the centre
centred with the fail flag showing
69. The coverage of the lLS glide slope with respect to the localizer centre line is:
a. +/-10° to 8 NM
+/-10° to 25 NM
C. +/-8° to 10 NM
d. +/-35° to 17 NM
70. The middle marker is usually located at a range of. ..,with an audio frequency
of .... ...and illuminates the. light.
4-6 NM 1300 Hz white
1 km 400 Hz white
C. 1 km 1300 Hz amber
d. 1km 400 Hz amber
71. The sequence of marker colours when flying an ILS approach is:
white, blue, amber
b blue, white, amber
C. blue, amber, white
d. amber, blue, white
72. The sensitive area of an ILS is the area aircraft may not enter when:
ILS operations are in progress
category IILS operations are progress
category / lILS operations are in progress
d. the ILS is undergoing calibration
73. The ILS localizer is normally positioned:
300 m from the downwind end of the runway
b 300 m from the threshold
C. 300 m from the upwind end of the runway
d. 200 m abeam the threshold
74. The audio frequency of the outer marker is:
3000 Hz
b. 400 Hz
1300 Hz
d. 1000 Hz

75. An aircraft is flying downwind outside the coverage of the ILS. The CDI indications
will be:

a. unreliable in azimuth and elevation

b. reliable in azimuth, unreliable in elevation
C. no indications will be shown
d. reliable in azimuth and elevation

76. The frequency band of the ILS glide path is:

UHF
b. VHF
SHF
d. VLF

77. In which band does the ILS glide path operate?

a. metric
b. centimetric
decimetric
d. hectometric

78. The coverage of MLS is ........ either side of the centre line to a distance of

a. 40° 40 NM
b. 40° 20 NM
C. 20° 20 NM
d 20° 40 NM
79. Distance on MLS is measured by:
a. measuring the time taken for the primary radar pulse to travel from the MLS
transmitter to the aircraft receiver
b. measuring the time taken for the secondary radar pulse to travel from the MLS
transmitter to the aircraft receiver
phase comparison between the azimuth and elevation beams
co-located DME

80. Which of the following is an advantage of MLS?

a. Can be used in inhospitable terrain
b. Uses the same aircraft equipment as ILS
C. Has a selective access ability
d. Is not affected by heavy precipitation
81. The frequency band of MLS is:
a. UHF
b. VHF
C. SHF
d. VLF

82. Primary radar operates on the principle of:

d. transponder interrogation
b. pulse technique
C. phase comparison
d. continuous wave emission

83. The definition of a radar display will be best with:

a. narrow beamwidth and narrow pulsewidth
narrow beamwidth and wide pulsewidth
C. wide beamwidth and narrow pulsewidth
wide beamwidth and wide pulsewidth
84. The main advantage of a continuous wave radar over a pulsed radar is:
a more complex equipment but better resolution and accuracy
removes the minimum range restriction
smaller more compact equipment
d. permits measurement of Doppler in addition to improved range and bearing
85. Which of the following systems use pulse technique?
1. secondary surveillance radar
2. airborne weather radar
3. distance measuring equipment
4. primary radar
all the above
b. 2 and 4 only
2 only
d. 1and 3 only
86. To double the range of a primary radar, the power must be increased by a factor of:

b 4
C. 8
d. 16

87 In aprimary pulsed radar the ability to discriminate in azimuth is a factor of:

pulse width
b beamwidth
C. pulse recurrence rate
d. rate of rotation

88. The maximum range of a ground radar is limited by:

pulse width
b peak pOwer
average power
pulse recurrence rate
89. What does pulse recurrence rate refer to?

the number of cycles per second

b. the number of pulses per second
the ratio of pulse width to pulse repetition period
d. the delay known as flyback dead time
90. The maximum PRF required for a range of 50 NM is:
a 300 pulses per second (pps)
b 600 ppS
1620 pps
d. 3280 pps
91. The best radar for measuring very short ranges is:
a a continuous wave primary radar
b a pulsed secondary radar
a pulsed primary radar
d. a continuous wave secondary radar
92. Which is the most suitable radar for measuring short ranges?
Millimetric pulse
b Continuous wave primary
Centimetric pulse
d. Continuous wave secondary
93. The main advantage of a slotted scanner is:
reduces side lobes and directs more energy into the main beanm
b removes the need for azimuth slaving
C. side lobe suppression
d. can produce simultaneous map and weather information
94. The maximum unambiguous (theoretical) range for a PRF of 1200 pps is:
134 NM
b 180 NM
C. 67 NM
d. 360 NM

95. The PRF of a radar is 450 pps. If the speed of light is 300 000 km/s, what is the
maximum range of the radar?
a 150 km
333 km
C. 666 km
d 1326 km

96. The best picture on a primary radar will be obtained using:

a. low frequency, narrow beam
b short wavelength, narrow beam
C. high frequency, wide beam
long wavelength, wide beam
97 Which of the following is a primary radar system?
a SSR
b DME
C. GPS
d. AWR

98. On what principle does primary ATC radar work?

a. Pulse technique
b Pulse comparison
C. Continuous wave
d. Transponder interrogation
99. The airborne weather radar (AWR) cannot detect:
snow
b. moderate rain
C. dry hail
d. wet hail

100. The frequency of AWR is:

a 9375 MHz
b. 937.5 MHz
C. 93.75 GHz
d. 9375 GHz

101. The use of the AWR on the ground is:

a not permitted
b permitted provided reduced power is used
C. permitted provided special precautions are taken to safeguard personnel and
equipment
d only permitted to assist movement in low visibility conditions
102. Which type of cloud does the AWR detect?
a Cirrocumulus
b. Altostratus
C. Cumulus
d. Stratus

103. The AWR uses the cosecant squared beam in the mode.

WEA
b CONT
C. MAP
MAN

104. On the AWR display the most severe turbulence will be shown:
a. in flashing red
b. by a black hole
C. by a steep colour gradient
d alternating red and white

105. On an AWR colour display, the sequence of colours indicating increasing water
droplet size is:

a. blue, green, red

b. green, yellow, red
C. black, amber, red
d. blue, amber, green
106. In an AWR with a 5° beamwidth, how do you orientate the scanner to receive returns
from clouds at or above your level?
0° tilt
b 2.5° uptilt
C. 2.5° downtilt
d. 5° uptilt
107. The ISO-ECHO circuit is incorporated in the AWR:
a. to allow ground mapping
to alert pilots to the presence of cloud
C. to display areas of turbulence in cloud
d. to allow simultaneous mapping and cloud detection
108. The main factors which affect whether an AWR will detect a cloud are:

a. the size of the water droplets and the diameter of the antenna reflector
b the scanner rotation rate and the frequency/wavelength
C. the size of the water droplets and the wavelength/frequency
d. the size of the water droplets and the range of the cloud
109. Inan AWR with a colour CRT, areas of greatest turbulence are indicated by:
a. iso-echo areas coloured black
b large areas of flashing red
C. iso-echo areas with no colour
d. most rapid change of colour
110. As a storm intensifies, the colour sequence on the AWR display will change:
a. black, yellow, amber
b. green, yellow, red
C. blue, green, orange
d. green, yellow, amber
111. The cosecant squared beam is used for mapping in the AWR because:
a. a greater range can be achieved
a wider beam is produced in azimuth to give a greater coverage
C. a larger area of ground is illuminated by the beam
d. it allows cloud detection to be effected whilst mapping
112. The AWR can be used on the ground provided:
1. the aircraft is clear of personnel, buildings and vehicles
conical beam is selected
3. maximum uptilt is selected
the AWR must never be operated on the ground
4
1 and 3
C. 1, 2 and 3
d. 2and 3
113. Doppler navigation systems use ......... to determine the aircraft ground speed
and drift.

a. DVOR
b. phase comparison of signals from ground stations
C. frequency shift in signals reflected from the ground
d. DME range measurement
114. Which axes is the AWR stabilized in?

a. Pitch, roll and yaw

Roll and yaw
C. Pitch and roll
d. Pitch only
115. With normal SSR mode Caltitude coding the aircraft replies by sending back a train
of up to 12 pulses contained between 2 framing pulses with:
a. 4096 codes in 4 blocks
b. 2048 codes in 3 blocks
4096 codes in 3 blocks
d. 2048 codes in 4 blocks

116. Why is the effect of returns from storms not a problem with SSR?
a. The frequency is too high
b. SSR does not use the echo principle
C. The PRF is jittered
d. By the use of MTI to remove stationary and slow moving returns