The runway designators at Sofia airport 09 - 27 seem offset on Google Earth. Why is that?
Emil Avramov
Last Update a year ago
The runway designator indicates the runway direction to the nearest 10 degrees, in degrees referenced to magnetic North. Google Earth's compass points towards the geographic North Pole (true North).
Runway 09 at Sofia has a magnetic direction of 089 degrees and true direction of 094 degrees.
Runway 27 at Sofia has a magnetic direction of 269 degrees and true direction of 274 degrees.
The difference between the true direction and magnetic direction at a given position is called variation. The variation in Sofia, Bulgaria is 5 degrees East.
In the aircraft, as a pilot, you have as a minimum a magnetic compass. When you line up runway 09, you shall see the numbers 09 in front of you written on the runway and the compass shall indicate around 090 degrees.
