How might cockpit displays indicate a loss of AC power?

How might cockpit displays indicate a loss of AC power?

• A. Immediate engine shutoff.
• B. External power indicator lights still on.
• C. Loss of display data, EICAS/ECAM warnings, reduced brightness, or standard caution indications.
• D. No changes; displays stay on.

Answer: (C)

When cockpit displays lose their AC power, the signs you’ll see are centered on the displays themselves failing to refresh data and dimming, with warning or advisory messages appearing. Primary indicators such as EICAS or ECAM pages may show no data or a degraded presentation, and the backlighting or brightness typically decreases. These cues collectively signal a power fault to the display system without implying immediate engine action or other unrelated faults. Immediate engine shutdown isn’t caused by a loss of display power, and external power lights staying on doesn’t guarantee full display operation since the buses feeding the displays may be affected. If power is restored or standby power is available, you might see some relief of these symptoms, but the characteristic response to AC power loss is degraded or blank data with caution/alert messages.

When cockpit displays lose their AC power, the signs you’ll see are centered on the displays themselves failing to refresh data and dimming, with warning or advisory messages appearing. Primary indicators such as EICAS or ECAM pages may show no data or a degraded presentation, and the backlighting or brightness typically decreases. These cues collectively signal a power fault to the display system without implying immediate engine action or other unrelated faults. Immediate engine shutdown isn’t caused by a loss of display power, and external power lights staying on doesn’t guarantee full display operation since the buses feeding the displays may be affected. If power is restored or standby power is available, you might see some relief of these symptoms, but the characteristic response to AC power loss is degraded or blank data with caution/alert messages.