Results
Q1. A DME station is located 1000 feet above MSL. An aircraft flying at FL 370, 15 NM away from the DME station, will have a DME reading of:
16 NM
Q2. Which of the following will give the most accurate calculation of aircraft ground speed?
A DME station sited on the flight route
Q3. An aircraft DME receiver does not lock on to its own transmissions reflected from the ground because:
they are not on the receiver frequency
Q4. The DME (Distance Measuring Equipment) operates within the following frequencies:
962 to 1213 MHz
Q5. A DME is located at MSL. An aircraft passing vertically above the station at flight level FL 360 will obtain a DME range of approximately:
6 NM
Q6. During a flight at FL 210, a pilot does not receive any DME distance indication from a DME station located approximately 220 NM away. The reason for this is that the:
aeroplane is below the ‘line of sight’ altitude
Q7. A typical frequency employed in Distance Measuring Equipment (DME) is:
1000 MHz
Q8. Distance Measuring Equipment (DME) operates in the:
UHF band and is a secondary radar system
Q9. For a conventional DME facility ‘Beacon Saturation’ will occur whenever the number of simultaneous interrogations exceeds:
100
Q10. On a DME, display counters rotating throughout their range indicates:
the airborne receiver is conducting a range search
Q11. The aircraft DME receiver is able to accept replies to its own transmissions and reject replies to other aircraft interrogations because:
pulse pairs are discreet to a particular aircraft
Q12. The aircraft DME receiver cannot lock on to interrogation signals reflected from the ground because:
aircraft transmitter and DME ground station are transmitting on different frequencies
Q13. In which situation will speed indications on an airborne Distance Measuring Equipment (DME) most closely represent the groundspeed of an aircraft flying at FL400?
When tracking directly towards the station at a range of 100 NM or more
Q14. The time taken for the transmission of an interrogation pulse by a Distance Measuring Equipment (DME) to travel to the ground transponder and return to the airborne receiver was 2000 micro-second. The slant range from the ground transponder was:
165 NM
Q15. What is the maximum distance between VOR and DME/TACAN ground installations if they are to have the same morse code identifier?
600 m
Q16. A DME in tracking mode subsequently experiences a reduction in signal strength will switch the equipment in the first instance to:
memory mode
Q17. Of what use, if any, is a military TACAN station to civil aviation?
It can provide DME distance
Q18. A DME that has difficulty obtaining a “lock-on”: (NOTE: PRF = pulse recurrence frequency, PPS = pulses per second)
stays in search mode but reduces PRF to max. 60 PPS after 15000 pulse pairs have been transmitted
Q19. DME channels utilise frequencies of approximately:
1000 MHz
Q20. A VOR and DME are co-located. You want to identify the DME by listening to the callsign. Having heard the same callsign 4 times in 30 seconds the:
DME callsign is the one with the higher pitch that was broadcast only once
Q21. In the DME system
The receive and the transmit frequency is always split by 63 MHz
Q22. The reason for using different frequencies for transmitting and receiving in the DME system
Is to prevent self-triggering of the receiving equipment by the transmitter
Q23. The airborne DME equipment will transmit pulse pairs at a comparatively high PRF
When first switched on and after a channel selection
Q24. In the DME system, responses in the aircraft equipment to answers to other aircraft is prevented
By an irregular change in pulse-pair PRF in every aircraft installation, and by making the receiver sensitive for reception only in a short period of time of around the anticipated time of arrival of the answer from the ground station
Q25. System, or beacon, saturation of the DME system
May occur when more than 100 aircraft are demanding replies from a single ground station
Q26. When VOR and DME stations are associated
They may be separated by as much as 600 metres if they are meant for en-route navigation
Q27. If a VOR station and a DME station, having different locations, are selected to provide a fix
All 3 answers above are correct
Q28. Consider the following statements on horizontal/slant distance when using DME:
The difference between the two distances will be negligible for en-route navigation when the indicated distance in NM is more than the height of the aircraft above the DME site, stated in thousands of feet
Q29. Using modern DME equipment meant for general navigation use, the accuracy expected is
+/-0,2 NM or 0,25% of the slant range, whichever is greater
Q30. What is the slant range error for an aircraft flying at 9000 feet absolute altitude above a DME located at elevation 2000 ft, when the slant range is 12 NM?
0,09 NM
