If an ADIRU is operating on battery power, what alert indication is presented to the ground crew?

If an ADIRU is operating on battery power, what alert indication is presented to the ground crew?

• A. An external horn sounds and the ADIRU and AVNCS light illuminates on the ground power panel
• B. The ground crew receives a beep on the handheld radio
• C. The cockpit voice recorder activates on the ground
• D. The APU starts

Answer: (A)

When the ADIRU is running off the aircraft’s battery on the ground, a specific alert is generated to warn ground crew that avionics are not powered by external ground power. The warning consists of an external horn sounding and the ADIRU and AVNCS indicators lighting on the ground power panel. The horn grabs attention and the illuminated indicators show exactly which systems are powered by the battery, so personnel know to treat the power situation accordingly and avoid misinterpreting the status. The other options don’t reflect this power-status alert—handheld radio beeps, the cockpit voice recorder activation, or the APU starting are not the indicators used for this condition.

When the ADIRU is running off the aircraft’s battery on the ground, a specific alert is generated to warn ground crew that avionics are not powered by external ground power. The warning consists of an external horn sounding and the ADIRU and AVNCS indicators lighting on the ground power panel. The horn grabs attention and the illuminated indicators show exactly which systems are powered by the battery, so personnel know to treat the power situation accordingly and avoid misinterpreting the status. The other options don’t reflect this power-status alert—handheld radio beeps, the cockpit voice recorder activation, or the APU starting are not the indicators used for this condition.