Which displays continue operating under emergency power?

Which displays continue operating under emergency power?

• A. EICAS, RMU 1/2, ISIS
• B. Only EICAS
• C. All cockpit displays
• D. EICAS, RMU 1/2, ISIS

Answer: (D)

When electrical energy is limited, only essential cockpit displays stay powered so the crew can monitor critical systems and maintain basic control. EICAS remains on because it shows engine parameters, system status, and any faults—information crucial for diagnosing and responding to abnormal or degraded conditions. RMU 1/2 stays powered to allow immediate radio tuning and access to essential communications and navigation functions, supporting situational awareness when power is limited. ISIS provides the standby instruments—the attitude indicator, airspeed, and altimeter—so the pilot can maintain orientation and basic flight data even if the primary displays aren’t available. Other cockpit displays rely on the normal power bus and aren’t kept on emergency power to conserve energy, so they would go dark. Therefore, the displays that continue operating under emergency power are EICAS, RMU 1/2, and ISIS.

When electrical energy is limited, only essential cockpit displays stay powered so the crew can monitor critical systems and maintain basic control. EICAS remains on because it shows engine parameters, system status, and any faults—information crucial for diagnosing and responding to abnormal or degraded conditions. RMU 1/2 stays powered to allow immediate radio tuning and access to essential communications and navigation functions, supporting situational awareness when power is limited. ISIS provides the standby instruments—the attitude indicator, airspeed, and altimeter—so the pilot can maintain orientation and basic flight data even if the primary displays aren’t available. Other cockpit displays rely on the normal power bus and aren’t kept on emergency power to conserve energy, so they would go dark. Therefore, the displays that continue operating under emergency power are EICAS, RMU 1/2, and ISIS.