RADIO NAVIGATION REVISION QUESTIONS Flashcards
- When would VDF be used for a position fix?
When declaring an emergency on 121.500 MHz
- What equipment does an aircraft need when carrying out a VDF letdown?
VHF radio
- Which of the following is an advantage of a VDF let down?
Only a VHF radio is needed in the aircraft
- What is the maximum range at which a VDF station at 325 ft can provide a service to an aircraft at FL080?
134 nm
- Which of the following statements regarding VHF direction finding (VDF) is most accurate?
It uses line of sight propagation
- What is the wavelength corresponding to a frequency of 375 kHz?
800 m
- A NDB transmits a signal pattern which is:
omni-directional
- The accuracy of ADF within the DOC by day is:
+/-5°
- 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:
044
- Two NDB’s, one 20 nm from the coast and the other 50 nm further inland. Assuming coastal error is the same for each, from which NDB will an aircraft flying over the sea receive the greatest error?
The NDB at 50 nm
- Which of the following is likely to have the greatest effect on the accuracy of ADF bearings?
Interference from other NDB’s, particularly at night
- Which of the following are all errors associated with ADF?
Mountain effect, station interference, static interference
- What action must be taken to receive a bearing from an ADF?
Both the loop and sense aerials must receive the signal
- When is coastal error at its worst for an aircraft at low level?
Beacon inland at an acute angle to the coast
- A radio beacon has a range of 10 nm. By what factor should the power be increased to achieve a range of 20 nm?
4
- Which of the following is the most significant error in ADF?
Static from Cb
- Which of the following may cause inaccuracies in ADF bearings?
Lack of failure warning, station interference, static interference
- The allocated frequency coverage of NDB’s is:
190 – 1750 kHz
- The principle used to measure VOR bearings is:
phase comparison
- When converting VOR and ADF bearings to true, the variation at the …… should be used for VOR and at the …… for ADF.
station, aircraft
- An aircraft flies from a VOR at 61N 013W to 58N 013W. The variation at the beacon is 13W and the variation at the aircraft is 5W. What radial is the aircraft on?
193
- In a conventional VOR the reference signal and the variable signal have a 30 Hz modulation. The variable signal modulation is produced by:
a 30 Hz rotation producing a 30 Hz modulation
- If the VOR accuracy has a limit of 1.0°, what is the maximum cross track error at 200 nm?
3.5 nm
- What is the maximum distance apart a VOR and TACAN can be located and have the same identification?
600m
- What is the maximum distance between VOR beacons designating the centreline of an airway (10 nm wide), if the expected VOR bearing error is 5.5°?
109 nm
- On a CVOR the phase difference between the AM and FM signals is 30°. The VOR radial is:
330
- 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:
600m
- Using a 5 dot CDI, how many dots would show for an aircraft on the edge of an airway at 100 nm from the VOR beacon?
1.5
- The maximum range an aircraft at FL370 can receive transmissions from a VOR/DME at 800 ft is:
275 nm
- When tracking a VOR radial inbound the aircraft would fly:
a great circle track
- Which of the following is a valid frequency (MHz) for a VOR?
112.20
- Using a VOR beyond the limits of the DOC may result in:
interference from other VOR’s operating on the same frequency
- An aircraft is flying a heading 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?
255
- When identifying a co-located VOR/DME the following signals are heard in the Morse code every 30 seconds:
4 identifications with the DME at a higher tone
- What is the maximum range a transmission from a VOR beacon at 169 ft can be received by an aircraft at FL012:
60 nm
- 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:
285, TO
- When tracking the 090 radial outbound from a VOR, the track flown is:
a great circle
- The frequency band of VOR is:
VHF
- On which radial from a VOR at 61N025E (VAR 13°E) is an aircraft at 59N025E (VAR 20°E)?
167
- 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?
16,000 ft
- For a conventional VOR a phase difference of 090° would be achieved by flying …………… from the beacon:
East
- At a range of 200 nm from a VOR, if there is an error of 1°, how far off the centreline is the aircraft?
3.5 nm
- The quoted accuracy of VOR is valid:
at all times
- Which of the following provides distance information?
DME
- Which of the following would give the best indication of speed?
A DME on the flight plan route
- What happens when a DME in the search mode fails to achieve lock-on?
It stays in the search mode, but reduces to 60 ppps after 15000 pulse pairs
- The most accurate measurement of speed by DME for an aircraft at 30,000 ft will be when the aircraft is:
tracking away from the beacon at 100 nm
- A DME beacon will become saturated when more than about …………… aircraft are interrogating the transponder.
100
- A typical DME frequency is:
1000 MHz
- The DME in an aircraft, cruising at FL210, fails to achieve lock on a DME at msl at a range of 210 nm. The reason for this is:
the aircraft is beyond line of sight range
- The aircraft DME receiver accepts replies to its own transmissions but rejects replies to other aircraft transmissions because:
the PRF of the interrogations is unique to each aircraft
- When an aircraft at FL360 is directly above a DME, at mean sea level, the range displayed will be:
6 nm
- A DME frequency could be:
1000 MHz
- An aircraft at FL360 is 10 nm plan range from a DME. The DME reading in the aircraft will be:
11.7 nm
- A DME transceiver does not lock onto its own reflections because:
the interrogation and reply frequencies differ
- What information does military TACAN provide for civil aviation users?
DME
- 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
- What are the DME frequencies?
960 – 1215 MHz
- 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:
165 nm
- The DME counters are rotating continuously. This indicates that:
the DME is trying to lock onto range
- On a DME presentation the counters are continuously rotating. This indicates:
the DME is in the search mode
- 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:
the aircraft is too low to receive the signal
- On an ILS approach you receive more of the 90 Hz modulation than the 150 Hz modulation. The action you should take is:
fly right and down
- The errors of an ILS localiser (LLZ) beam are due to:
ground reflections
- The amplitude modulation of the ILS outer marker is …………… and it illuminates the ……………. light in the cockpit.
400 Hz blue
- The principle of operation of the ILS localiser transmitter is that it transmits two overlapping lobes on:
the same frequency with different amplitude modulations
- The ILS glideslope transmitter generates false glidepaths because of:
multiple lobes in the radiation pattern
- A category III ILS system provides accurate guidance down to:
the surface of the runway
- A HSI compass rose is stuck on 200°. When the aircraft is lined up on the centreline of the ILS localiser for runway 25, the localiser needle will be:
centred
- The coverage of the ILS glideslope with respect to the localiser centreline is:
+/-8° to 10 nm
- The middle marker is usually located at a range of …………….., with an audio frequency of ……………. and illuminates the …………….. light.
1 km, 1300 Hz, amber
- The sequence of marker colours when flying an ILS approach is:
blue, amber, white
- The sensitive area of an ILS is the area aircraft may not enter when:
category II/III ILS operations are in progress
- The ILS localiser is normally positioned:
300 m from the upwind end of the runway
- The audio frequency of the outer marker is:
400 Hz
- An aircraft is flying downwind outside the coverage of the ILS. The CDI indications will be:
unreliable in azimuth and elevation
- The frequency band of the ILS glidepath is:
UHF, decimetric
- In which band does the ILS glidepath operate?
UHF, decimetric
- Primary radar operates on the principle of:
pulse technique
- The definition of a radar display will be best with:
narrow beamwidth and narrow pulsewidth
- The main advantage of a continuous wave radar over a pulsed radar is:
removes the minimum range restriction
- Which of the following systems use pulse technique?
- secondary surveillance radar
- airborne weather radar
- distance measuring equipment
- primary radar
all the above
- To double the range of a primary radar, the power must be increased by a factor of:
16
- In a primary pulsed radar the ability to discriminate in azimuth is a factor of:
beamwidth
- The maximum range of a ground radar is limited by:
pulse recurrence rate
- What does pulse recurrence rate refer to?
the number of pulses per second
- The maximum PRF required for a range of 50 nm is:
1620 pps
- The best radar for measuring very short ranges is:
a continuous wave primary radar
- Which is the most suitable radar for measuring short ranges?
continuous wave primary
- The main advantage of a slotted scanner is:
reduces sidelobes and directs more energy into the main beam
- The maximum unambiguous (theoretical) range for a PRF of 1200 pps is:
67 nm
- The PRF of a radar is 450 pps. If the speed of light is 300000 kps, what is the maximum range of the radar?
333 km
- The best picture on a primary radar will be obtained using:
short wavelength, narrow beam
- Which of the following is a primary radar system?
AWR