Warning Systems - Altitude Alert
Altitude alerting occurs when approaching or departing the MCP-selected altitude. Total absence of altitude alerting indicates system failure.
Approaching Selected Altitude
At 900 feet prior to reaching the selected altitude, the ALT light on each pilot's altimeter illuminates. At 300 feet prior to reaching the selected altitude, the ALT lights extinguish.
Deviating From a Selected Altitude
When deviating by 300 feet from the selected altitude:
- The master CAUTION lights illuminate.
- The caution aural sounds
. - The EICAS caution message ALTITUDE ALERT is displayed.
- The ALT ALERT light illuminates.
When deviating more than 900 feet from the selected altitude, or upon returning to within 300 feet of the selected altitude:
- The master CAUTION lights extinguish.
- The EICAS caution message is no longer displayed.
- The ALT ALERT light extinguishes.
Altitude alerting is reset when the airplane returns to within 300 feet of the altitude selected or a new altitude is selected which is within 300 feet of the airplane altitude.
Deviation alerting is inhibited in flight with the Landing Gear Down and Locked. Altitude deviation alerting can be reset by changing the selected altitude.
