BENDIXKing AeroNav 910 Pilot's Manual page 91

Extreme Attitude Depiction
At extreme pitch/flight path angles, both positive and negative,
the horizon line will detach from the terrain (or traditional
blue/brown AI) such that there will always be a strip of blue/sky or
brown/ground visible to aid in initiating unusual attitude
recoveries.
High/low pitch chevrons are also displayed in those extreme
pitch/flight path angle situations and point toward the horizon as
well.
The following SynVis-related failure conditions result in an
automatic transition from the SynVis scene to the traditional
blue/brown AI:

Loss of GPS position or track

Inability to convert GPS altitude to MSL altitude

Loss of pitch or roll data

Invalid or frozen terrain database data

Movement beyond the latitude limits of SynVis (valid
within the range 60°S latitude to 75°N latitude)
89000039-010
Rev 1 May 2019
AeroNav 900/880 Series Pilot's Guide
SVS Subsystem 2-23