High Speed Protection
High speed protection prevents aircraft damage due to excessive speed. High speed
protection activates slightly above VMO/MMO, at the speed depicted by a green equal
sign.
When high speed protection activates:
• The autopilot(s) disconnect.
• Nose down pitch trim is inhibited.
• The flight control computers attempt to limit further acceleration by commanding a gentle pitch up. This protection limits maximum airspeed by automatically increasing the aircraft’s pitch attitude even if the sidestick is held full forward.
• The bank angle limit is reduced from 67° to 45° (limit marks do not move).
"Positive spiral stability becomes active at all bank angles (instead of the usual 33° in normal law). Therefore, the sidestick must be held to maintain any bank angle. If the sidestick is released the aircraft returns to a bank angle of 0°.
The CRC and MASTER WARN lights activate and an O/SPEED (overspeed) warning is displayed on the E/WD. The CRC can only be silenced by slowing down or pushing the EMER CANC pb. Holding the sidestick full forward will allow some exceedance of the limit speed (this permits limited maneuvering if necessary). The amount of forward sidestick held and
the rate at which the sidestick was moved forward affects how far the aircraft’s speed will increase above VMO/MMO. If the pilot holds the sidestick full forward, the speed will stabilize above VMO/MMO. When the sidestick is returned to neutral, the speed will return to VMO/MMO. High speed protection is deactivated when the aircraft decreases below VMO/MMO."
I wouldn't want to fly an airplane that thinks for itself, especially one that will override the pilot.