Chart
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The chart is drawn in magnetic north, like the radials of a VOR. Drag the aircraft or the VOR station with mouse or finger.
The shaded halves show where the flag reads TO (orange) and FROM (cyan) for the course set in the OBS. The dashed line through the station is where the flag flips.
Keyboard (click the chart first): ← → heading, [ ] OBS.
Instruments
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Heading indicator: where the nose points. It has nothing to do with the VOR indication.
VOR / CDI: the OBS card sets the course. The needle shows where that course line is: needle right means the course is to your right. Each dot is 2°, full scale is 10°.
Tip: drag sideways on the VOR instrument or use the mouse wheel to twist the OBS.
Position readouts are hidden during this exercise.
Training
Move things around and let the coach explain what the instruments are telling you. Everything updates live.
The aircraft is hidden. Look only at the instruments, then click on the chart where the aircraft could be. The heading is shown on purpose: does it matter?
The aircraft is hidden. Twist the OBS until the needle is centered with the correct flag, then press Check.
What the needle is telling you
- 01Tune
Set the VOR frequency (108.00 to 117.95 MHz) from the chart.
- 02Identify
Listen to the Morse ident and compare it with the chart. No ident, no navigation.
- 03Twist
Set the desired course in the OBS: the radial outbound, or the course to the station inbound.
- 04Read
Check the flag first (TO or FROM), then the needle: it shows where the course line is.
- 05Fly
Turn toward the needle to intercept, then hold the needle centered and correct for wind.
A VOR indicator only knows where you are and which course you selected. It does not know where your nose points. Turn the aircraft on the spot and nothing on the CDI moves.
How a VOR works
The station transmits two 30 Hz signals. Their phase difference tells your receiver on which radial you are. There are 360 radials, all measured from the station and referenced to magnetic north.
Radial = QDR (magnetic bearing from the station). Course to the station = QDM, always the radial ± 180°.
Reading the needle
The needle shows where the selected course line is, as seen when facing the course direction. Needle right, course right. One dot is 2°, full scale (5 dots) is 10° or more.
1 in 60 rule: at 60 NM, 1° off course is about 1 NM. At 30 NM one dot (2°) is about 1 NM, close to the station the same dot is only a few hundred metres.
The TO / FROM flag
Draw a line through the station at right angles to your selected course. On the side the course leads to after the station the flag reads FROM, on the other side TO.
The flag shows OFF near that line (abeam), right above the station, out of range or when the signal is unusable.
During maintenance a VOR may still transmit but with the ident removed (in the US it may send TST). Never navigate on a VOR you have not identified.
The ident is a Morse code, not a voice announcement — select NAV on the audio panel to monitor it.