DME Flashcards
What frequency is DME
962-1213 MHZ (UHF)
What is the selected frequency for DME
108-117.95 (VHF)
What type of frequency is transmitted by a DME
Muttered pulse repetition frequency (PRF)
How do you avoid echo with a DME
Transponder will send back +/- 63 MHz
How do you avoid error if lots of a/c are on the same DME
Have a 50 microsecond calibration delay
What is a radar mile
12.36 microseconds / NM
When will a DME show 0
Ok touchdown for ils
What is the pulse rate for search mode DME
15,000 pulses @ 150 pps
If no response
= 60pps
Once search mode for DME finds something what does it do
Go into tracking mode
= 30 pps
If loss of signal from DME what happens
Goes into memory mode
= same rate for 20-30 seconds
= prevents cone of confusion
What is beacon saturation DME
100 a/c on DME at same time
Discriminates again weaker signals
NOTHING TO DO WITH DISTANCE
What is the identification for DME
3 letter ident
Same as VOR it fo located (within 1000’)
What will you hear in the ident for DME
3 x VOR then 1 x DME over a 45 second period
DME is higher pitch tone
What is the DME error
+/- 0.25 Nm + 1.25% of DME distance
DME / p is more accurate
What is a TACAN
Military VOR / DME
VOR for military use only
DME dan be used by civilians
