I just grabbed the EGPWS manual from our technical library...it helps when trying to understand something like this to have the book to refer to. Here is what it says:
Mode 6 provides audio call-outs for descent below predefined altitudes and minimums. The call-outs produce
aural output indications, but do not produce visual indications.
A “MINIMUMS-MINIMUMS” callout is provided based on the decision height discrete with gear down (less
than 90 Kts or less than 200 ft AGL in fixed gear aircraft). With Low Altitude Mode selected or with gear up
(greater than 90 Kts), the message “ALTITUDE ALTITUDE” sounds when transitioning below the selected
decision height.
An optional input gives the ability to force the Mode 6 audio level to lower audio volume. This lets the aircrew
control the Mode 6 volume level with activation of windscreen rain removal, or if they desire lower volume
call-outs at all times.
The EGPWS uses engine torque sensing to detect autorotation. The autorotation call-outs occur at 200 ft and
100 ft. If the gear is not down by 400 ft, an audio “TOO LOW, GEAR” warning sounds.
An excessive bank angle warning is provided based on Radio Altitude, Roll Attitude and Roll Rate. The
“BANK ANGLE” aural warning is given twice and then suppressed unless the roll angle increases by an
additional 20%.
A tail strike warning function is based on Radio Altitude, Pitch Attitude, Pitch Rate and Barometric Altitude
Rate. The voice message “TAIL TOO LOW” sounds continuously while in the warning boundary. Failure
Annunciations Monitor the EGPWS through an annunciator on the annunciator panel. The GPWS INOP
annunciator illuminates to indicate that a mode in the GPWS function is inoperative or degraded.
And importantly, this written in bold in a CAUTION box
The pilot must maintain visual contact with all terrain and obstacles at all times when using the Low
Altitude mode. The Low Altitude mode must not be engaged during IFR conditions. The look down
angle is reduced with Low Altitude engaged. Warning time is greatly reduced.