FMS prediction and trajectory

The vertical profile shows planned waypoints and altitude changes. It also shows a trajectory line based on the current flight-path angle.

The FSS VNAV page ^[201] says TOC and TOD appear on the MFD flight-plan overlay. The MFD General page ^[203] describes altitude-profile markers as the relative positions of transition points such as TOC and TOD. Check the labels and markers shown in your aircraft.

Vertical-profile source

Ensure the FMS and intended active plan are being shown.

TOC and TOD

Locate the predicted TOC or TOD where available and relate it to the current aircraft position.

Read the restrictions

Compare waypoint altitudes and constraints against the FPL and chart.

Compare the trajectory

A trajectory line based on the current flight path is not a guarantee that the aircraft will remain on the planned profile.

Descent response

Use vertical deviation, speed, thrust, ALTSEL and the FMA to confirm the descent is developing as intended. ^[203]