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When it comes to navigation in aircraft, a reliable compass is crucial. However, compasses are not perfect and can be affected by various errors. In this blog post, we will explore the different types of compass errors that occur in aircraft and how they can impact navigation.

1. Magnetic Deviation

One common compass error is magnetic deviation. This error is caused by the presence of magnetic fields within the aircraft, such as those generated by electrical systems or ferrous materials. These magnetic fields can interfere with the compass needle, causing it to deviate from the true magnetic north.

2. Magnetic Variation

Another important compass error to consider is magnetic variation. Magnetic variation refers to the angular difference between true north and magnetic north at a specific location. This error occurs due to the Earth's magnetic field not aligning perfectly with the geographic North Pole.

3. Oscillation

Oscillation is a type of compass error that causes the compass needle to swing back and forth rapidly, making it difficult to get an accurate reading. This error can be caused by turbulence or vibrations within the aircraft.

4. Dip Errors

Dip errors occur when the aircraft is flying at different altitudes. As the altitude changes, the Earth's magnetic field can have varying effects on the compass needle. For example, when flying at higher altitudes, the compass needle may tilt downwards, leading to incorrect readings.

5. Acceleration and Deceleration Errors

During acceleration or deceleration, compass errors can occur due to the inertia of the compass card. When the aircraft undergoes changes in speed, the compass card may not immediately adjust, resulting in temporary errors in the displayed heading.

6. Northerly Turning Error

The northerly turning error is a compass error that affects the accuracy of the compass when making turns in certain directions. When turning towards the north or south, the compass tends to indicate a shallower bank angle than the actual bank angle of the aircraft.

7. Magnetic Dip

Magnetic dip is an error caused by the inclination of the Earth's magnetic field. As the aircraft moves closer to the Earth's magnetic poles, the compass needle becomes more susceptible to dip errors. These errors can result in inaccurate readings, especially when flying near the magnetic poles.

8. Precession

Precession is a gradual drift of the compass needle over time. This error occurs due to various factors, such as friction and changes in temperature. It is important for pilots to regularly check and recalibrate their compasses to compensate for precession.

Conclusion: Navigating Compass Errors

Understanding the different types of compass errors that occur in aircraft is essential for pilots. By being aware of these errors and their potential impacts on navigation, pilots can take appropriate measures to compensate for them. Regular compass checks, proper calibration, and staying updated with magnetic variation charts are crucial for accurate navigation.

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Aviation English Asia has been offering part time and full time courses in Hong Kong since 2009.

All courses are available in Hong Kong. Check the schedule above for details.


Aviation English Asia has been offering part time courses in Vietnam since 2014.

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