02 Radio Aids Flashcards

Question

Which of the following will give the most accurate calculation of aircraft ground speed?

Answer 1

A DME station sited on the flight route ..................... The DME can provide groundspeed based on the rate of change of distance, however, this will only be correct when flying directly towards or away from the station, i.e. the station is situated on the flight route.

Answer 2

A change in the direction of the plane of polarisation due to reflection in the ionosphere. .......................... The night effect will alter the polarisation of the signal when it is refracted in the ionosphere. This change of polarisation will contaminate the surface wave coverage area reducing the effectiveness of the loop antenna thus effectively reducing the range of the NDB.

Answer 3

4.9 NM .................. DME indicates Slant Range (direct line of sight distance) to the ground station. Slant Range can be calculated using Height and Ground Range. In this case, the Slant Range is given as 5 NM. Similarly, Ground Range can be calculated using Slant Range and Height. The aircraft is at 6 000 ft above the DME station. Aircraft Height = 6 000 ft / 6 000 ft Aircraft Height = 1 NM Using Pythagoras’ Theorem, the Ground Range can now be calculated. Ground Range = v(Slant Range² - Height²) Ground Range = v(5² - 1²) Ground Range = v(25 - 1) Ground Range = v24 Ground Range = 4.9 NM Answer: 4.9 NM

Answer 4

the slant range and centre the DME-station. ............................ Drawing a circular position line based on a DME distance will be based on the slant range as the DME distance as indicated by the DME unit is the direct line of sight distance to the station which is a combination of the ground distance and the height of the aircraft above the station. The circular position line will be centred on the ground station.

Answer 5

4 .............. If you double transmitter power you will increase your range by the square root of 2. Which is 1.414 time the range. therefore 4 x pwr = 10nm x 1.414 = 14.14 x 1.414 = 19.99nm

Answer 6

the time interval between pulse pairs is unique to that particular aircraft

Answer 7

increase with displacement above or below the glidepath. ...................... The amount of difference in depth of modulation (the difference in signal strength of the 90 Hz and 150 Hz signals compared to each other) is proportional to the angular displacement from the localiser centreline or optimal glideslope.

Answer 8

A DME ground station is only able to process 2700 ppps.

Answer 9

It does not have a signal failure warning flag.

Answer 10

ADF ................. The ADF is the system that is most sensitive to static interference, and a nearby thunderstorm may render the ADF useless as it turns into a lightning finder.

Answer 11

025 ............... The heading of the aircraft is irrelevant in order to establish the position on a HSI. The course selector is set to 200º and with a TO indication this means that the selected radial is the reciprocal, i.e. 200º – 180º = 020º. As the deviation bar is showing half scale deviation to the right, the aircraft is 5º to the left of the selected radial when facing the VOR. Therefore, the aircraft is on radial 020º + 5º = 025º.

Answer 12

Moving card ADF and RMI. ..................... The RMI will automatically indicate the magnetic bearing to the NDB provided it shows the correct magnetic heading from the compass system. An RBI with a rotating card can indicate the magnetic bearing to the NDB provided the compass card is aligned with the aircraft compass at all times.

Answer 13

Non Directional Beacon.

Answer 14

When using an HSI you must set the course arrow to the localizer front-beam course.

Answer 15

The DME operating frequencies are in the UHF frequency band. .................................... The DME operates in the UHF band. The DME will indicate the direct distance between the aircraft and the station, also known as the slant range, i.e. a combination of the ground distance and the height of the aircraft above the station. A DME may be co-located with a VOR, ILS or NDB or may be a stand alone installation. If obtaining a fix from two DME stations the position fix will be ambiguous as there are two possible positions with the circular position lines intersecting at two places.

Answer 16

The Doppler effect is used to create a signal which is received by the aircraft's VOR-receiver as a frequency modulated signal.

Answer 17

VHF band. .......................... The system frequency for marker beacons is 75 MHz, i.e. in the VHF band, regardless of whether it is outer, middle or inner/airway marker. Their morse code and tone (and associated colour) will be different but due to their limited range, they will not interfere with each other.

Answer 18

inner marker (if available). ........................ The outer marker (OM) is identified by a blue flashing light and a 400 Hz tone transmitted as continuous dashes. The middle marker (MM) is identified by an amber flashing light and a 1300 Hz tone transmitted as alternating dots and dashes. The inner marker (IM) is identified by a white flashing light and a 3000 Hz tone transmitted at 6 dots per second

Answer 19

uneven propagation over irregular ground surfaces .................... An error that is associated with VORs is the effect of the surface causing bending or scalloping of the signals. Static interference, quadrantal error and night effect are all errors mainly associated with NDBs.

Answer 20

blue - amber - white ......................... The outer marker (OM) is identified by a blue flashing light and a 400 Hz tone transmitted as continuous dashes. The middle marker (MM) is identified by an amber flashing light and a 1300 Hz tone transmitted as alternating dots and dashes. The inner marker (IM) is identified by a white flashing light and a 3000 Hz tone transmitted at 6 dots per second

Answer 21

outer marker.

Answer 22

167° ................. Since the aircraft is on the same meridian as the VOR ( Since the aircraft is South of the VOR, the true bearing of the aircraft from the VOR is 180º (aircraft and VOR on the same meridian with the VOR at a higher latitude (N61) the aircraft at a lower latitude (N59)). A VOR radial is defined as the magnetic bearing of the aircraft from the station when applying the variation at the station, and since the variation at the station is 13ºE, the magnetic bearing of the aircraft is 180ºT ± 13E = 167ºM. Therefore, the aircraft is on radial 167. Since the aircraft is on the same meridian as the VOR (E01000), the aircraft will either be due North or South of the VOR. With the VOR at N4500 and the aircraft at N4400, the aircraft is South of the VOR, i.e. the true bearing of the aircraft from the VOR is 180º. A VOR radial is defined as the magnetic bearing of the aircraft from the station when applying the variation at the station, and since the variation at the station is 10ºW, the magnetic bearing of the aircraft is 180ºT ± 10ºW = 190ºM. Therefore, the aircraft is on radial 190º.

Answer 23

It is affected by the power of the transmitter.

Answer 24

QTE accurate to +/-2°

Answer 25

skywave distortion of the null position and is maximum at dawn and dusk ............................ The night effect is greatest at dusk and dawn and is caused by increased presence of sky waves within the area where the surface wave is present. The sky wave will mix with the surface wave and the resultant is a less defined or altered null position making obtaining an accurate bearing more difficult. This interference is not affected by the direction from the NDB to the aircraft.

Answer 26

2 and 3. .............. The localiser transmit in the VHF band (108.10 MHz – 111.95 MHz). The outer marker transmit in the VHF band (75 MHz). The glideslope transmit in the UHF band (329.15 MHz – 335 MHz). The locator transmit in the LF/MF band (190 kHz – 1750 kHz).

Answer 27

inner marker.

Answer 28

increasing altitude. ..................... As VDF operates in the VHF band (normal ATC communications), the signals will propagate as space waves, i.e. requiring line of sight between the transmitter and the receiver. The best way to improve range is therefore to increase the altitude of the transmitter.

Answer 29

TO, half scale deflection to the right.

Answer 30

the card should be rotated so that the aircraft heading is at the top of the indicator.

Answer 31

centimetric.

Answer 32

Fluctuating indications of the needle on the RMI. ................................. One result of the night effect is the inability for the ADF to obtain a defined bearing which will result in the needle fluctuating, also known as a hunting needle.

Answer 33

SHF ............... The MLS transmit in the SHF band (5031 MHz – 5091 MHz).

Answer 34

When there is no difference in depth of modulation, the strength pf the 90 Hz and 150 Hz signals are equal, i.e. the aircraft is on the localiser centreline and the optimum glideslope.

Answer 35

right drift

Answer 36

is caused by the refraction from the aircraft's fuselage and is compensated for.

Answer 37

Range within "line of sight", and maximum 200 NM.

Answer 38

The aircraft from which the weakest pulse pairs are received.

Answer 39

Inner marker.

Answer 40

These transmissions may interfere with the ILS localizer signal which may lead to erroneous localizer deviation indication.

Answer 41

The BFO circuit imposes a tone onto the carrier wave to make the NDB's ident audible.

Answer 42

300 m beyond the threshold. .............................. The glideslope antenna is normally placed alongside the runway around 300 m from the threshold of the landing runway.

Answer 43

2.5° ...................... Full scale deflection for the localiser indication is 2.5º and for the glidepath indication 0.7º,

Answer 44

When the term "radial" is used in reference to VOR it means: ..................... When referring to a VOR, a 'radial' is the magnetic bearing FROM the station

Answer 45

VHF ............ VORs transmit in the VHF frequency band (hence the name VHF omni-range) (30 MHz – 300 MHz) using the frequency band 108.00 MHz – 117.95 MHz.

Answer 46

middle marker.

Answer 47

Aeroplane is below the line of sight altitude.

Answer 48

Can be used as a published non-precision approach.

Answer 49

Audio: 1300 Hz, alternating dots and dashes. Visual: Amber light flashes.

Answer 50

decimetric. ................... The DME frequency range is 960 MHz to 1215 MHz. Using a medium frequency of 1100 MHz, the wavelength is: Wavelength (?) = speed of light (c) ÷ frequency (f) = 300 000 000 m/s ÷ 1 100 000 000 Hz = 0.273 m This is in the decimetric band (0.1 m – 0.9 m).

Answer 51

205° and 295°

Answer 52

static interference - night effect - absence of failure warning system

Answer 53

7.0 NM ......................... Convert altitude into nautical miles FL240 = 24,000 ft 24,000 ft / 6,080 ft = 3.95 nm DME Range² = Ground Range² + Height² 8² = Ground Range² + 3.95² 64 = Ground Range² + 15.58 Transpose formula to solve Ground Range Ground Range² = 64 - 15.58 Ground Range² = 48.42 Ground Range = v48.42 Ground Range = 6.96 nm The closest answer is 7.0 nm

Answer 54

On the non-approach end of the runway about 300 m from the runway on the extended centreline

Answer 55

Time reference scanning beam.

Answer 56

+/- 40° of the runway centre-line.

Answer 57

1, 2 and 3.

Answer 58

1 NM inside the airway southern boundary

Answer 59

+ or - 1.5 NM .................... DME-N is calibrated to operate to an accuracy of ±0.25 nm + 1.25% of the DME distance. Accuracy at 100 nm = ±0.25 nm + (100 nm x 1.25%) = ±1.5 nm

Answer 60

3.5 NM ....................... This question is really a 1 in 60 rule question rather than a VOR issue. Hopefully you will recall the 1 in 60 formula: Track Error Angle = (dist off track x 60) / range Therefore: 1 = (dist off track x 60) / 200 Therefore: dist off track = 200 / 60 = 3.33nm

Answer 61

Scalloping.

Answer 62

17 NM over a sector of 35° each side of the centre line.

Answer 63

Within 2000 feet of each other.

Answer 64

The Relative Bearing of the NDB should be equal (in magnitude and sign) to the experienced Drift Angle.

Answer 65

2.5 dots. ............................ While performing an ILS approach, the maximum safe "fly-up" indication of the glide path needle (assuming a 5-dot indicator) is 2.5 dots.

Answer 66

15 m above the horizontal plane containing the threshold.

Answer 67

The middle marker.

Answer 68

053° (T) .................... This is a very poorly worded question and a number of assumptions have to be made: (a) The selected course on the Course Deviation Indicator (CDI) is 240°; (b) The deviation bar is centred. Given these assumptions, the aircraft will be positioned on the R-240° radial and in order to fly directly to the station the aircraft would have to fly along a track, which is the reciprocal to this radial. The bearing of the radial is measured in degrees magnetic at the ground station; that being the case, any application of magnetic variation is applied at the station. Reciprocal of R-240° = 240°M - 180° = 060°M inbound Then, apply magnetic variation ( as measured at the ground station) Variation West Magnetic Best (True is less) 060°M - 7°W = 053°T True Track = 053°T

Answer 69

Inner ....................... The outer marker (OM) is identified by a blue flashing light and a 400 Hz tone transmitted as continuous dashes. The middle marker (MM) is identified by an amber flashing light and a 1300 Hz tone transmitted as alternating dots and dashes. The inner marker (IM) is identified by a white flashing light and a 3000 Hz tone transmitted as continuous dashes.

Answer 70

Magnetic north at the station. ........................ The bearing of the aircraft is measured at the VDF station and will be referenced to true or magnetic North at the station.

Answer 71

null. ................. When the aircraft is on the localiser centreline (the localiser deviation bar is centred) the strength of the 90 Hz and 150 Hz signals are the same, i.e. there is no difference in depth of modulation.

Answer 72

1.0° to the left.

Answer 73

Scalloping has a negative effect on the accuracy of navigation.

Answer 74

To make the ILS-localizer receiver less susceptible to interference from commercial FM-stations (radio and television).

Answer 75

in sectors A & B

Answer 76

the surface of the runway

Answer 77

Receiver, Antenna, Display

Answer 78

180 NM .................. VHF direction finding (VDF) signals propagate as space waves, i.e. line of sight. The maximum theoretical range is calculated using the following formula: VHF range = 1.23 x (√height of the station + √height of the aircraft) VHF range = 1.23 x (√height of the station + √height of the aircraft) = 1.23 x (√1024 ft + √13 000 ft) = 179.6 nm

Answer 79

190 kHz to 1750 kHz. .......................... The frequency band for the NDB/ADF system is 190 to 1750 kHz.

Answer 80

150 FT/MIN

Answer 81

memory mode ...................... If the DME receiver lose its signal it will switch to memory mode (maintaining the current rate of change of distance) for a finite amount of time. If the signal loss is longer than the defined time the DME will indicate a loss of signal.

Answer 82

At a certain moment of time, both the phase of the reference signals and of the variable signals are equal for both aircraft.

Answer 83

190 NM .................... The maximum theoretical range of a VOR is calculated using the following formula: VHF range = 1.23 x (vheight of the station + vheight of the aircraft) VHF range = 1.23 x (vheight of the station + vheight of the aircraft) = 1.23 x (v0 ft + v23 000 ft) = 186.5 nm

Answer 84

A precision instrument approach and landing, with a DH lower than 200ft but not lower than 100ft, and an RVR not less than 350m.

Answer 85

At the same height as the aircraft.

Answer 86

The mountain effect is caused by reflections onto steep slopes of mountainous terrain which may cause big errors in the bearing.

Answer 87

decrease in the aircraft's rate of descent of 50 FT/MIN ........................ Rate of descent in ft/min for a 3º glideslope can be found by multiplying the groundspeed by 5. If the aircraft is flying slower, the rate of descent must be decreased in order to follow the same glideslope as when the speed was greater. The change in rate of descent can be found by substituting the actual groundspeed by the change in groundspeed. Rate of descent = groundspeed x 5 = 10 kts x 5 = 50 ft/nm

Answer 88

an ILS frequency.

Answer 89

The Airborne installation switching to the memory mode for about 10 to 15 seconds.

Answer 90

the transmission can be interrupted to avoid reflection by stationary objects.

Answer 91

Localiser only.

Answer 92

Initiate a go-around.

Answer 93

All markers transmit at 75 MHz.

Answer 94

4. ................. The glideslope transmit in the UHF band (329.15 MHz – 335 MHz). The localiser transmit in the VHF band (109.10 MHz – 111.95 MHz). The locator transmit in the LF/MF band (190 kHz – 1750 kHz). The outer marker transmit in the VHF band (75 MHz).

Answer 95

184 NM ................... The maximum theoretical range of a VOR is calculated using the following formula: VHF range = 1.23 x (vheight of the station + vheight of the aircraft) VHF range = 1.23 x (vheight of the station + vheight of the aircraft) = 1.23 x (v609 ft + v15 000 ft) = 181 nm

Answer 96

slight curves that can be followed by large aircraft.

Answer 97

050° .............. With the OBS set to 235º and a TO indication the aircraft is to the northeast of the VOR. If the deviation bar was centred the aircraft would on a radial that is reciprocal to the selection, i.e. 235º – 180º = 055º. With half scale “fly left” indication the aircraft is 5º to the right of the selected radial when facing the VOR, i.e. on radial 055º – 5º = 050º.

Answer 98

Flight altitude.

Answer 99

DH 100 ft, RVR 300 m.

Answer 100

When tracking directly towards the station at a range of 100 NM or more

Answer 101

DME ............... VOR = VHF Omni-directional Ranging Equipment ADF = Automatic Direction Finder VDF = VHF Direction Finder DME = Distance Measuring Equipment

Answer 102

slant range. ................... The DME distance is the direct distance between the aircraft and the station, also known as the slant range, i.e. it is a combination of the ground distance and the height of the aircraft above the station.

Answer 103

3 and 10 NM

Answer 104

110 NM ...................... The maximum theoretical range of a VOR is calculated using the following formula: VHF range = 1.23 x (SQRTheight of the station + SQRTheight of the aircraft) VHF range = 1.23 x (SQRTheight of the station + SQRTheight of the aircraft) = 1.23 x (SQRT100 ft + SQRT6400 ft) = 110.7 nm

Answer 105

+/-0.25 NM plus 1.25% of the distance measured.

Answer 106

the required ground wave is being contaminated by sky waves

Answer 107

Distinguish its own replies from those triggered by other aircraft

Answer 108

450 FT/MIN ................... Rate of descent in ft/min for a 3º glideslope can be found by multiplying the groundspeed by 5. Rate of descent = groundspeed x 5 = 90 kts x 5 = 450 ft/nm

Answer 109

to prevent that DME interrogation pulse pairs being received by the aircraft after reflection on the earth surface.

Answer 110

to provide the ATC controller with bearings of aircraft in the absence of radar. .................... VDF (VHF direction finding) will sense the direction from which a signal arrives at the receiver antenna. This will provide the ATC officer with a bearing towards the aircraft assisting in establishing/confirming the aircraft position in the absence of radar. This bearing can also be used to provide steering information to assist the aircraft in flying towards the VDF station.

Answer 111

Loop and Sense

Answer 112

A blue light and 2 dashes a second of a 400 Hz modulated tone.

Answer 113

non-precision approach guidance for the reciprocal of the main approach runway.

Answer 114

0.7° above or below the correct glide path.

Answer 115

UHF frequency with a minimum range of 10 NM.

Answer 116

Two overlapping lobes on the same VHF carrier frequency

Answer 117

a radiation pattern which is amplitude modulated by a 90 Hz and a 150 Hz signal.

Answer 118

It changes from interrogation to interrogation.

Answer 119

non precision approach on the reciprocal runway of the precision approach runway

Answer 120

They may result in bearing errors.

Answer 121

6 dots per second continuously.

Answer 122

6.8 NM ......................... The DME will indicate the line of sight distance to the station, i.e. including a combination of ground distance and aircraft height above the station. Directly overhead the station the DME will indicate the aircraft height in nm, 41 000 ft ÷ 6080 ft/nm = 6.7 nm

Answer 123

The mountain effect is caused by reflections onto steep slope of mountainous terrain which may cause big errors in the bearing.

Answer 124

provides basically the same approach capabilities as ILS.

Answer 125

100 ............ Beacon saturation occurs when the number of interrogators exceeds 100. At this time the processing time for all interrogations add up to the time difference between each set of interrogation pulses from the DME unit in tracking mode, i.e. each DME unit will have its slot of the total capacity of the ground station. Any more interrogators will not receive a reply from the ground station as here are no processing slots available.

Answer 126

QTE ................. The 'Q Code' for a true bearing from a VDF station is a 'QTE' Background Information The following 'Q Code' descriptors are: * QDM - Magnetic Bearing TO * QDR - Magnetic Bearing FROM * QUJ - True Bearing TO * QTE - True Bearing FROM

Answer 127

LF/MF NDBs used as an aid for final approach. ..................... A locator beacon is an NDB whose primary function is to act as an approach aid, therefore, a locator will often have a short range defined as 10 nm – 25 nm. Because of the shorter range the transmission power can be reduced.

Answer 128

the magnetic great circle direction from the beacon. .................... A VOR radial is defined as the magnetic bearing from the station and the direction of the radial will follow a great circle track as radio waves follow great circle tracks. In some cases the radial can be given with reference to true North (typically in areas close to the magnetic poles).

Answer 129

Interference from other NDBs, particularly at night

Answer 130

0.2NM ............... DME-P (precise) error for systems installed after 1 Jan 1989 should not exceed 0.2NM. DME-N (narrow) error should not exceed 0.25NM + 1.25% of the measured distance.

Answer 131

aircraft manoeuvring near the runway may disturb guidance signals

Answer 132

at about 200 ft AAL.

Answer 133

105 NM ............... The greatest cross track error acceptable is 5nm off the airway centreline. We assume that the aircraft flies out of one beacon and then switches over half way to home to the next beacon so the greatest possible error will occur at the half way point. The 1 in 60 rule can be used here. Expressed as a formula it is: distance off track = track error angle distance gone 60 or, distance gone = distance off track x 60 track error angle The maximum distance off track is 5nm, track error angle is 5.5º so distance to half way = 5 x 60 ÷ 5.5 = 54.5nm distance between the beacons is twice that, 109 nm.

Answer 134

1.35° above the horizontal to 5.25° above the horizontal and 8° each side of the localiser centreline ................... The glide slope coverage of an ILS goes from 0.45 to 1.75 times the glidepath angle so for our 3° glideslope this is 0.45 x 3° = 1.35° and 1.75 x 3° = 5.25°

Answer 135

The range depends on the elevation of the antenna located on the ground and on the altitude of the aircraft.

Answer 136

75 MHz. ............... The system frequency for marker beacons is 75 MHz, i.e. in the VHF band, regardless of whether it is outer, middle or inner/airway marker. Their morse code and tone (and associated colour) will be different but due to their limited range, they will not interfere with each other.

Answer 137

75 MHz ................. The system (transmission) frequency for all marker beacons is 75 MHz.

Answer 138

the difference in depth of modulation.

Answer 139

at the VOR

Answer 140

At night the D layer in the ionosphere disappears and the signals reach the E and F layers which reflect them back.

Answer 141

measures the difference in depth of modulation of the two transmitted signals.

Answer 142

metric. ............... The ILS frequency range is 108.10 MHz to 111.95 MHz. Using a medium frequency of 110 MHz, the wavelength is: Wavelength (λ) = speed of light (c) ÷ frequency (f) = 300 000 000 m/s ÷ 110 000 000 Hz = 2.73 m This is in the metric band (1 m – 9.99 m).

Answer 143

the modulation from both lobes at equal depth.

Answer 144

failure of the VOR station to stay within required limits can cause removal of identification and the navigation components from the carrier wave to cease.

Answer 145

east ............ With the conventional VOR the phase difference between the variable phase and the reference phase represent the radial the aircraft is on, i.e. if the phase difference is 90º, the aircraft is on radial 090 or East of the station.

Answer 146

outer marker. .................... The outer marker (OM) is identified by a blue flashing light and a 400 Hz tone transmitted as continuous dashes. The middle marker (MM) is identified by an amber flashing light and a 1300 Hz tone transmitted as alternating dots and dashes. The inner marker (IM) is identified by a white flashing light and a 3000 Hz tone transmitted at 6 dots per second

Answer 147

the airborne receiver is conducting a range search

Answer 148

amplitude modulation. ........................ The ILS use amplitude modulation (AM) to transmit the 90 Hz and 150 Hz signals of the lobes for both localiser and glideslope.

Answer 149

The variable signal antenna rotates at 30 times per second whilst the reference signal is produced from a fixed antenna.

Answer 150

Localizer transmitter: 300 metres behind end of runway, Glide path transmitter: 300 metres behind threshold, Middle Marker: 1000 metres from threshold, Outer Marker: 4 NM from threshold.

Answer 151

they are not on the receiver frequency

Answer 152

The direction of the ADF pointer will change, the direction of the VOR pointer will not change.

Answer 153

208° ............ When situated on the R-028° radial FROM the VOR the OBS should be selected to 208° to obtain a centred needle with a TO indication.

Answer 154

1000 MHz ............. The DME frequency range is 960 MHz to 1215 MHz.

Answer 155

135°. ................... The a/c is not heading 090! the compass rose is stuck on 090. the relative bearing of the beacon is 135 degrees from the actual aircraft heading (which we are not given) The beacon position is referenced clockwise from the nose of the a/c. The original compass rose card for the ADF was fixed ie a piece of paper stuck behind a needle with north at the top. Relative bearings are always taken clockwise around the card. In this case there is 135 degrees between the nose of the a/c (indicating 090) and the pointer indicating 225 degrees (to the NDB) on the card. The maths is easy 225-090 = 135 degrees.

Answer 156

010° .......... Since the aircraft is North of the VOR, the true bearing of the aircraft from the VOR is 360º. A VOR radial is defined as the magnetic bearing of the aircraft from the station when applying the variation at the station, and since the variation at the station is 10ºW, the magnetic bearing of the aircraft is 000ºT ± 10W = 010ºM. Therefore, the aircraft is on radial 010.

Answer 157

The rotation of the variable signal at a rate of 30 times per second gives it the characteristics of a 30 Hz amplitude modulation

Answer 158

the VHF band. ............... The localiser transmit in the VHF band (108.10 MHz – 111.95 MHz). The glideslope transmit in the UHF band (329.15 MHz – 335 MHz).

Answer 159

75 MHz. ................ The system frequency for marker beacons is 75 MHz, i.e. in the VHF band, regardless of whether it is outer, middle or inner/airway marker. Their morse code and tone (and associated colour) will be different but due to their limited range, they will not interfere with each other.

Answer 160

0.5 degrees ............... Full scale defection for the localiser display indicates 2.5º displacement from the localiser centreline. If there is 5 dots either side of centre on the CDI, each dot represent 2.5º ÷ 5 = 0.5º per dot.

Answer 161

20 NM from touchdown inbound and 8° displaced from the localiser centreline.

Answer 162

204 NM .................. The maximum theoretical range of a VOR is calculated using the following formula: VHF range = 1.23 x (vheight of the station + vheight of the aircraft) VHF range = 1.23 x (vheight of the station + vheight of the aircraft) = 1.23 x (v340 ft + v21 000 ft) = 200.9 nm

Answer 163

The 150 Hz modulation predominates to the right of the centre line

Answer 164

hectometric or kilometric.

Answer 165

VOR and NDB.

Answer 166

10° or more

Answer 167

hear the IDENT of some NDB stations radiating a continuous wave signal

Answer 168

the VOR will be approached along radial 070.

Answer 169

The middle marker indicates the position for the decision for a missed approach during a CAT I approach due too bad visibility.

Answer 170

The difference in depth between the 90 Hz modulation and the 150 Hz modulation.

Answer 171

UHF and VHF bands. ............... The ILS use transmissions in the VHF band for the localiser signal (108.10 MHz – 111.95 MHz) and in the UHF band for the glideslope signal (329.15 MHz – 335 MHz).

Answer 172

A TVOR has a limited range.

Answer 173

167° ............ The groundspeed will be most correct when the aircraft is flying directly towards or away from the DME. The aircraft and the VOR are on the same longitude (E09800), i.e. the aircraft is either due North or due South of the VOR. As the VOR is at N3612 and the aircraft at N3415, the aircraft is South of the VOR making the direction of the aircraft from the VOR 180ºT. As a VOR radial is magnetic referenced to the variation at the VOR, the aircraft is on radial: 180ºT – 13ºE = 167º.

Answer 174

Audio: 1300 Hz, alternating dots and dashes. Visual: Amber light flashes.

Answer 175

760 FT/MIN .................. For glideslopes with an angle of other than 3º use the following calculation: Rate of descent (ft/min) = (groundspeed ÷ 60) x glideslope angle x 100 Rate of descent = (groundspeed ÷ 60) x glideslope angle x 100 = (140 kts ÷ 60) x 3.25 x 100 = 758 ft/min

Answer 176

Scalloping causes rapid indicator changes from side to side of the intended approach path which can not be followed by the aircraft. ......................... Scalloping is an error that is associated with both localiser and glideslope and are small variations (or wave like bends) occurring to the signal due to external influences. This scalloping will cause smaller deflection of the indicator that may be too rapid for the aircraft to follow.

Answer 177

10 - 25 NM ................... A locator beacon is an NDB whose primary function is to act as an approach aid, therefore, a locator will often have a short range defined as 10 nm – 25 nm.

Answer 178

1.5 | ...........

Answer 179

2.5 dots .................... The aircraft's position relative to the runway extended centreline (C/L) is shown by the Course Deviation Indicator (CDI) vertical Localiser (LOC) needle, which indicates aircraft position left or right of C/L. If the needle is displaced to the left the aircraft is right of C/L. If the needle is displaced to the right the aircraft is left of C/L. The aircraft's position relative to the glide path (GP) is shown by the Course Deviation Indicator (CDI) horizontal Glide Path (GP) needle, which indicates aircraft position above or below GP. If the needle is displaced upwards the aircraft is below GP. If the needle is displaced downwards the aircraft is above GP.

Answer 180

omnidirectional ........................... The radiation pattern from an NDB is omnidirectional, i.e. of equal signal strength in all directions from the antenna. It can be said to operate like any simple radio transmitter.

Answer 181

rho-theta information from a terminal VOR/DME can be obtained. ...................... For the purpose of the exams: Terminal VORs are allocated frequencies in the range 108.00 - 112.00 MHz, which is shared with ILS. En-Route VORs are allocated frequencies in the range 112.00 - 117.95 MHz.

Answer 182

(i) 8° (ii) 10 ..................... The glideslope coverage area is within 0.45 and 1.75 x the glideslope angle and 8º either side of the localiser centreline to a distance of 10 nm.

Answer 183

10° each side of the localiser centre.

Answer 184

DH 200 ft; RVR 550 m.

Answer 185

Left of selected course, DME distance decreasing

Answer 186

interrogator transmits a relatively low number of pulse pairs per second.

Answer 187

the DVOR antenna is comparatively larger than the CVOR antenna.

Answer 188

outer marker.

Answer 189

null. ................ When the aircraft is on the localiser centreline (the localiser deviation bar is centred) the strength of the 90 Hz and 150 Hz signals are the same, i.e. there is no difference in depth of modulation.

Answer 190

1, 2, 3 and 4.

Answer 191

Conventional radio navigation is based on raw data like information from navigation aids and measured air data.

Answer 192

the area directly overhead a VOR

Answer 193

ILS encounters difficulties because of surrounding buildings and/or the terrain or interference from local music stations.

Answer 194

Fly right and fly down

Answer 195

Figure B ............... The course selected on the course selector is 060º and with that selection the indicator shows a TO indication and a fly right indication. As there is a TO indication, the aircraft is on an inbound course that is 10º to the left of the selected course (060º), i.e. 060º + 10º = 070º. The aircraft is on radial 070º + 180º = 250º. The RMI will indicate the aircraft heading (010º) and the tail of the needle will point at the present radial, i.e. 250º, and the head of the needle will point towards the station along that radial, i.e. a course of 250º – 180º = 070º.

Answer 196

may receive false course indications

Answer 197

Time reference scanning beam (TRSB).

Answer 198

great circle track ....................... As the question does not specify short or long distances and as we know magnetic track changes over distance (even short ones) therefore the answer has to be a Great Circle Track.

Answer 199

reference to true or magnetic north at the station.

Answer 200

inner marker.

Answer 201

less than 300 kt and 7 NM. | ......................

Answer 202

600 FT/MIN ................ Rate of descent in ft/min for a 3º glideslope can be found by multiplying the groundspeed by 5. Rate of descent = groundspeed x 5 = 120 kts x 5 = 600 ft/nm

Answer 203

fly left and up | ................

Answer 204

VHF at civil aerodromes and UHF at military aerodromes

Answer 205

400 Hz, blue

Answer 206

With propagation over sea the range will be greater than the range with propagation over land.

Answer 207

phase difference between the variable signal and the reference signal.

Answer 208

064° with the TO flag showing

Answer 209

"Request QDR". ................... The Q codes used in relation to direction finding are: - QDM: Magnetic bearing to the station. - QDR: Magnetic bearing from the station. - QUJ: True bearing to the station. - QTE: True bearing from the station.

Answer 210

hear the IDENT of NDBs using NON A1A transmissions ....................... NON A1A are the older type where you need to select BFO to ON to hear the IDENT. NON A2A are the newer type where the BFO does not need to be selected on.

Answer 211

inland and the bearing crosses the coast at an acute angle .................... The effect of coastal refraction will increase with increasing distance of the NDB from the coast. If the aircraft is on a bearing that cross the coast at a right angle, the coastal refraction will be non-existent regardless of the distance the NDB is inland from the coast. An acute angle between the bearing and the coast will give the greatest effect of coastal refraction.

Answer 212

Separate azimuth and elevation transmitters, DME facility ...................... The MLS utilise separate azimuth (horizontal guidance), elevation (vertical guidance) and DME-P (range) facilities.

Answer 213

two VDF's at different locations, able to take bearings simultaneously on the transmitted frequency.

Answer 214

The transponder reply carrier frequency differs by 63 MHz from that of the interrogation signal.

Answer 215

The difference in depth between the 90Hz modulation and the 150Hz modulation.

Answer 216

ILS glide path transmitter. .................... The glideslope transmit in the UHF band (329.15 MHz – 335 MHz). The localiser transmit in the VHF band (108.10 MHz – 111.95 MHz). The locator transmit in the LF/MF band (190 kHz – 1750 kHz). The outer marker transmit in the VHF band (75 MHz).

Answer 217

middle marker.

Answer 218

left with 'TO' showing

Answer 219

a continuous series of alternate dots and dashes, the dashes keyed at the rate of 2 dashes per second, and the dots at the rate of 6 dots per second.

Answer 220

It is insensitive to geographical site and can be installed at sites where it is not possible to use an ILS

Answer 221

4 NM from the threshold.

Answer 222

962 to 1213 MHz

Answer 223

False beams will only be found above the correct glide path.

Answer 224

more of the 150 Hz localiser signal than the 90 Hz localiser signal.

Answer 225

109.15 MHz ............... The localiser frequency range (as well as the ILS system frequency) is 108.10 MHz to 111.95 MHz with the first decimal place being odd numbers only, i.e. 108.10, 108.15, 108.30, 108.35, 108.50 etc.

Answer 226

190 - 1750 kHz

Answer 227

DME Morse ident is the one with the higher pitch that was broadcast only once

Answer 228

Non-precision approach on the reciprocal runway of the precision approach runway.

Answer 229

Non-directional radio beacon.

Answer 230

An ILS-like approach

Answer 231

LF N0N/A2A

Answer 232

entry into airspace from an area where SSR operation has not been required

Answer 233

VOR with a limited range used in the terminal area. .................... The TVOR, or terminal VOR, is a VOR with limited range used within a terminal area as part of the approach and departure structure at an airport.

Answer 234

signal bending by the aircraft metallic surfaces

Answer 235

6 NM ......... The DME will indicate the line of sight distance to the station, i.e. when the aircraft is directly overhead, the indicated distance will be equal to the aircraft altitude (height). 36 000 ft ÷ 6080 ft/nm = 5.9 nm

Answer 236

2 dashes per second continuously.

Answer 237

reflection.

Answer 238

alternate dots and dashes and an amber light flashing

Answer 239

+/- 40° about the nominal courseline out to a range of 20 NM

Answer 240

omnidirectional

Answer 241

Category II/III operations are in progress.

Answer 242

the aircraft is passing the NDB on a line perpendicular with the coastline.

Answer 243

commence a go-around because obstacle clearance is no longer assured.

Answer 244

metric. ................ The VOR frequency range is 108.00 MHz to 117.95 MHz. Using a medium frequency of 110 MHz, the wavelength is: Wavelength (?) = speed of light (c) ÷ frequency (f) = 300 000 000 m/s ÷ 110 000 000 Hz = 2.72 m This is in the metric band (1 m – 9.99 m).

Answer 245

a test VOR

Answer 246

Local thunderstorm activity

Answer 247

100 NM ................. Remember an NDB station's range is directly proportional to the square root of it's transmitter range. NEW Power ÷ OLD Power = (New Range ÷ Old Range)² 100 ÷ 25 = (New Range ÷ 50)² square root of 4 = New Range ÷ 50 2 X 50 = 100 NM New Range = 100 NM

Answer 248

All answers given are correct.

Answer 249

interference from other transmitters

Answer 250

phase comparison

Answer 251

middle marker.

Answer 252

relative bearing on a fixed card indicator

Answer 253

Night effect

Answer 254

NDB is a ground equipment, and ADF is an airborne equipment.

Answer 255

smaller from the beacon that is 20 NM inland

Answer 256

The Pulse Repetition Frequency of the pulse-pairs transmitted by the interrogator varies, for each interrogator, in a unique rhythm.

Answer 257

Decreases with range.

Answer 258

outer marker.

Answer 259

90 Hz and 150 Hz lobes at equal depth.

Answer 260

The aircraft from which the weakest pulse pairs are received.

Answer 261

The interrogation does not start before pulse-pairs of the tuned DME-station are received.

Answer 262

Position C

Answer 263

signal must be received by both the sense and loop aerials

Answer 264

the range increases and the accuracy decreases.

Answer 265

Bearings 0°-30° degrees to the coastline

Answer 266

Slant range can be provided because the VHF frequency has a paired DME UHF frequency

Answer 267

(i) the same (ii) modulation frequencies

Answer 268

fact that the variable phase is frequency modulated instead of amplitude modulated (as with CVOR).

Answer 269

123 NM ........................ The maximum theoretical range of a VOR is calculated using the following formula: VHF range = 1.23 x (vheight of the station + vheight of the aircraft) VHF range = 1.23 x (vheight of the station + vheight of the aircraft) = 1.23 x (v0 ft + v10 000 ft) = 123 nm

Answer 270

VHF Direction Finder.

Answer 271

the transmitted power.

Answer 272

108 to 117.95 MHz

Answer 273

6.8 NM ........... 1NM = 6000ft FL410 = 41000ft 41000/6000 = 6.8NM

Answer 274

OM, MM, IM (if available).

Answer 275

320° ............... If the aircraft is on radial or QDR 075º, it is to the east northeast of the NDB and the bearing to the NDB (QDM) will be 075º + 180º = 255º. The aircraft is on a heading of 295º, i.e. heading a bit to the right of the inbound course to the NDB. Since the needle of the RBI will point at the NDB, it will point a bit to the left of the top of the instrument (360º), making 320º the only sensible alternative. This can also be calculated: Relative bearing = magnetic bearing to – magnetic heading = 255º – 295º = -40º + 360º = 320º

Answer 276

obtain three dimensional positions. .................... In order to obtain a 3 dimensional fix it is necessary to have guidance both horizontally (azimuth), vertically (elevation) and range (DME-P).

Answer 277

600 m ............... The maximum distance between VOR and DME/TACAN ground installations, if they are to have the same Morse code identifier, is 600m.

Answer 278

284° with the TO flag showing

Answer 279

approximately a quarter of the scale.

Answer 280

behind the aeroplane symbol with the FROM flag showing

Answer 281

Radial 135°, relative bearing unknown

Answer 282

Aircraft height is not limiting for the reception of signals from the NDB.

Answer 283

+ or - 0.25 NM plus 1.25% of the distance measured

Answer 284

increases linearly with respect to the angular displacement from the centerline.

Answer 285

VHF .............. VOR operate in the VHF frequency band with frequency range 108.00 MHz to 117.975 MHz.

Answer 286

200 feet above the runway threshold

Answer 287

Give preference to the aircraft with the strongest transmissions

Answer 288

A precision facility DME

Answer 289

In 40 seconds the DME ident will sound once.

Answer 290

10 to 25 NM

Answer 291

In a period of 40 seconds the DME ident will be heard once on an audio frequency of 1350 Hz.

Answer 292

alternating dots and dashes at a rate of 2 dashes per second and 6 dots per second

Answer 293

FL80 .............. VHF direction finding (VDF) signals propagate as space waves, i.e. line of sight. The maximum theoretical range is calculated using the following formula: VHF range = 1.23 x (√height of the station + √height of the aircraft) Rearranged to find the height of the aircraft gives the following calculation: Height of the aircraft = ((VHF range ÷ 1.23) - √height of the station)² = ((113 nm ÷ 1.23) - √169)² = 6220 ft Therefore, the minimum pressure altitude at which the aircraft can fly would be FL 63 (6300 ft), however, this is not on offer. In that respect, the lowest pressure altitude on offer is FL 80. NOTE: It is understood that the 'correct' answer in the ECQB may be FL 60, owing to the question author incorrectly using a multiplication factor of 1.25 (Learning Objectives state 1.23) If you see this question in your examination, you are advised to notify your ATO.

Answer 294

An Azimuth transmitter and an Elevation transmitter operating on a shared frequency and a DME. ................. The Microwave Landing System comprises three separate antennas: Azimuth antenna, for lateral navigation Elevation antenna, for vertical navigation DME/P (Precision DME) for distance measurement

Answer 295

approximately 2 NM. ................... The DME will indicate the line of sight distance to the station, i.e. including a combination of ground distance and aircraft height above the station. Directly overhead the station the DME will indicate the aircraft height in nm, 12 000 ft ÷ 6080 ft/nm = 2 nm

Answer 296

025 ................... The heading of the aircraft is irrelevant in order to establish the position on a OBI. The OBS is set to 200º and with a TO indication this means that the selected radial is the reciprocal, i.e. 200º – 180º = 020º. As the deviation bar is showing half scale deviation to the right, the aircraft is 5º to the left of the selected radial when facing the VOR. Therefore, the aircraft is on radial 020º + 5º = 025º.

Answer 297

The DME frequency is paired with the localizer frequency so only the localiser frequency is set.

Answer 298

UHF band and uses two frequencies ................. The DME frequency range is 960 MHz to 1215 MHz which is within the UHF frequency band (300 MHZ – 3000 MHz) and use two frequencies separated by 63 MHz for interrogation and reply.

Answer 299

The Relative Bearing of the NDB should be kept 000°.

Answer 300

VHF transmitter-receiver operating in the 118 MHz to 136 MHz range.

Answer 301

To prevent self-triggering of the receiving equipment by the transmitter.

Answer 302

It only requires a VHF radio to be fitted to the aircraft

Answer 303

The height of the transmitter and of the receiver.

Answer 304

only found above the correct glideslope

Answer 305

aircraft transmitter and DME ground station are transmitting on different frequencies

Answer 306

Rotates at 30 revolutions per second

Answer 307

NDB: aircraft position VOR: beacon position

Answer 308

C & D and the signal bends towards the coast

Answer 309

time between the transmission and reception of radio pulses

Answer 310

adjusts the gain to reply to the 100 strongest signals

Answer 311

The Doppler effect is used to create a signal which is received by the aircraft's VOR receiver as a frequency modulated signal.

Answer 312

It can provide DME distance

Answer 313

030° ................ The radial from a VOR is determined by the phase difference between the reference signal and the variable signal. If there is 30º difference between them the receiver will be on radial 030º regardless of whether the radial is based on a conventional VOR or a doppler VOR.

Answer 314

measures the phase difference between the reference phase and the variable phase of the signal.

Answer 315

(1) secondary (2) slant (3) transponder

Answer 316

108 MHz and 111.975 MHz.

Answer 317

QUJ ............ The 'Q Code' for a true bearing to a VDF station is a 'QUJ' Background Information The following 'Q Code' descriptors are: * QDM - Magnetic Bearing TO * QDR - Magnetic Bearing FROM * QUJ - True Bearing TO * QTE - True Bearing FROM

Answer 318

aeroplane is below the 'line of sight' altitude ....................... The maximum theoretical range of a DME is calculated using the following formula: VHF range = 1.23 x (SQRTheight of the station + SQRTheight of the aircraft) VHF range = 1.23 x (SQRTheight of the station + SQRTheight of the aircraft) = 1.23 x (SQRT0 ft +SQRT21 000 ft) = 178.2 nm With the approximate distance between the aircraft and the station being 220 nm, this is beyond line of sight and the maximum range at the present altitude.

Answer 319

inner marker.

Answer 320

Many different approaches to the same runway may be defined by a single set of ground equipment.

Answer 321

2.5° offset from the localiser centreline.

Answer 322

in the SHF band, 300 kHz frequency separation giving 200 available channels. ................ The MLS transmit in the SHF band (5031 MHz – 5091 MHz) with 300 kHz (0.3 MHz) spacing giving 200 available channels.

Answer 323

Full scale deflection left with a 'from' indication

Answer 324

in what magnetic direction the signal left the VOR antenna and the identification of the station ................. The information carried by a signal emitted from a VOR is the magnetic direction the signal left the VOR antenna and the identification of the station. Background Information The VOR transmitter emits two signals, on the same carrier wave frequency: * Reference Phase signal * Variable Phase signal These signals are in phase with each other along a bearing of 000°M (Magnetic North) from the VOR, i.e. the phase difference between the two signals is 000°. On all other bearings from the station there is a phase difference between the two signals. The phase difference is equal to the magnetic bearing from the VOR, e.g. along a bearing of 045°M from the VOR, the reference phase signal leads the variable phase signal by 045° (phase difference = 045°) The two signals are received at the aircraft on the VHF NAV receiver, which identifies the radial the aircraft is currently on from the phase difference between the two signals, and outputs this information to the cockpit display equipment. The station identification code is also transmitted on the carrier wave.

02 Radio Aids Flashcards

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