Acceleration/deceleration errors primarily occur when flying on which headings?

Acceleration and deceleration errors are most pronounced when flying on east or west headings due to the way the magnetic compass operates. The compass is heavily influenced by the Earth's magnetic field and its relationship with the aircraft's direction of travel.

When an aircraft is headed east or west, it is experiencing a perpendicular relationship to the Earth's magnetic lines of force, which can lead to significant variations in compass indications during acceleration and deceleration. For instance, during acceleration while flying east, the compass may lag and indicate a turn toward the north. Conversely, during deceleration, it may indicate a turn toward the south. These variations can create confusion for pilots if they rely solely on the compass for navigation during these phases.

On other headings, such as north or south, the magnetic compass is more aligned with the Earth's magnetic field, which tends to reduce these specific errors. Therefore, the most substantial impact on compass accuracy due to acceleration and deceleration happens when the aircraft is oriented toward the east or west. Understanding this phenomenon is crucial for pilots to accurately interpret their heading and make necessary corrections for safe navigation.