The Flight Path Marker (FPM), also known as a Velocity Vector, is displayed on the PFW once the aircraft is above 30 knots. The FPM can be enabled and disabled when the synthetic terrain feature (SVT) is enabled, and is not available when synthetic terrain is not enabled. The FPM is track-based rather than heading-based and depicts the approximate projected climb or decent path of the aircraft. Certain operations, steep approaches or high rates of climb scenarios, can cause the FPM to deviate significantly from the trajectory of the aircraft, in which case the FPM will move to a section beyond the limits of the display. For more information on the FPM and AFCS modes, refer to the AFCS chapter.