Which statement best defines position error?

• A. Error in the indication of the altimeter, ASI, and VSI caused by the air at the static system entrance not being absolutely still.
• B. Error in the indication of the compass due to magnetic variation.
• C. Error in GPS altitude readings due to satellite geometry.
• D. Error in the attitude indicator caused by rapid pitch changes.

Answer: (D)

Position error is the temporary discrepancy on the attitude indicator caused by the gyroscope’s inertia when the aircraft’s attitude changes rapidly. Because the gyro resists sudden change, the horizon on the instrument lags behind the actual attitude during quick pitch movements and only realigns as the gyro catches up. This makes the displayed attitude momentarily inaccurate, which is exactly what “position error” describes for the attitude indicator. The other scenarios describe errors in different instruments (static-port related errors affecting altimeter/airspeed/vsi, magnetic variation affecting the compass, GPS altitude issues from satellite geometry), not the transient lag of the attitude indicator during rapid pitch changes.