What is the northerly turning error associated with?

The northerly turning error is specifically associated with compass errors that occur during turns when an aircraft is heading towards or away from magnetic North or South. This phenomenon happens because of the way magnetic compasses respond to changes in heading, particularly in high latitudes where the magnetic dip angles are pronounced.

When an aircraft turns from a northerly heading, the compass tends to lag behind the actual heading due to the magnetic field's inclination, leading the pilot to believe they are on a different heading than they truly are. This results in the compass indicating a heading that is off from the true heading, which can lead to navigational errors.

Understanding this error is vital for pilots, especially in maintaining accurate heading during critical phases of flight, such as takeoff, navigation, and approach. Recognizing the nuances of compass behavior helps ensure safe and precise aerial navigation, especially when operating in regions where magnetic variation may be significant.