> For the complete documentation index, see [llms.txt](https://docs.flightsim-studio.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.flightsim-studio.com/e-jet-series/systems-guide/main-panel/primary-flight-display-pfd/vertical-navigation-vnav.md).

# VERTICAL NAVIGATION (VNAV)

### VNAV ALTITUDE WAYPOINT CONSTRAINT READOUT

* Displays an active waypoint constraint altitude automatically honored by the FMS prior to arrival at the preselected altitude.

![VNAV altitude constraint readout](https://cdn.document360.io/417c2d4d-fdb8-4d4d-b11d-011fe445d776/Images/Documentation/primary-flight-display-pfd-image-r3m7i15a.png)

### VNAV TARGET ALTITUDE BUG

* Displayed when a VNAV target altitude is valid and the FMS is the primary NAV source.

### VERTICAL TRACK ALERT (VTA)

Magenta **VTA** on the PFD (above the vertical deviation scale). Flashes reverse video for 5 seconds, then remains steady.

A VTA is issued when:

* Within 1,000 ft of capturing an altitude constraint that is not the altitude preselect.
* In cruise, 1 minute before TOD.
* 1 minute before resuming a climb or descent from a constrained waypoint.
* 1 minute before a step climb (cruise).

An aural VTA is also issued.

### TOC / TOD ON THE MAP

When FMS is the map source, **TOC** and **TOD** are shown on the MFD flight-plan overlay as altitude transition points on the vertical profile.