Tuning and Orientation
To tune the VOR equipment, turn on the power switch, select the required frequency, and adjust the volume until the VOR beacon aural identification signal can be clearly heard and identified as the required beacon. Ensure that the OFF alarm flag has disappeared as this indicates that the visual indicators are serviceable.
Now turn the Omni Bearing Selector (OBS) until the Deviation Indicator is centred and TO is shown by the TO/FROM indicator. The bearing then shown in the Bearing Selector Window is the magnetic bearing to the VOR beacon.
Homing Directly to the VOR Beacon
After orienting the aircraft as detailed above, turn the aircraft onto the magnetic heading shown in the Bearing Selector Window and then, changing heading as necessary, maintain the Deviation Indicator in the central position.
With the TO/FROM Indicator showing TO, the aircraft heading should be changed toward the Deviation Indicator to re-centre it if it deviates from the central position as the Deviation Indicator shows the position of the Radial relative to the aircraft position. If a cross-wind component exists, this will be indicated by the Deviation Indicator’s moving to the side from which the wind is blowing.
The drift angle is the difference between the aircraft heading necessary to maintain the Deviation Indicator in the central position, and the bearing being maintained.
Continue flying with the Deviation Indicator central along the bearing towards the VOR beacon until the Deviation Indicator swings from side to side. The aircraft is now over the VOR beacon, and, if flight is continued on the same heading the Deviation Indicator will return to the central position and the TO/FROM indicator will show FROM.
The Radial is the reciprocal of the bearing being maintained.
Homing Directly to the Beacon