Dear Team,

When simulating L UPPER AVNCS smoke, the OVHD panel SMOKE red indication on the AVNCS button, extinguishes after all AC electrical buses are powered off (i.e. Engines and APU for an emergency evacuation). Although this SMOKE indication is dependent on DC Electrical feed. On Battery power the DC ESS BUS ensures the avionics smoke detectors remain powered and active. Also the essential CIDS/SDF channel is tied to the essential DC power backed by the battery network to maintain critical smoke detection during emergency configs. So the discrete red SMOKE legend inside the AVNCS SMOKE pushbutton is driven by the active detection loop/FWS output. Because of this circuit is hosted on the ESS DC the light stays energized. This helps the crew see if the condition persists after shutting down engines on the ground.

Hope this helps.

Kind regards,

Luis B.

Edited 58 minutes ago58 min by BallinaPilot
Editorial / typo

43 minutes ago, BallinaPilot said:

Dear Team,

When simulating L UPPER AVNCS smoke, the OVHD panel SMOKE red indication on the AVNCS button, extinguishes after all AC electrical buses are powered off (i.e. Engines and APU for an emergency evacuation). Although this SMOKE indication is dependent on DC Electrical feed. On Battery power the DC ESS BUS ensures the avionics smoke detectors remain powered and active. Also the essential CIDS/SDF channel is tied to the essential DC power backed by the battery network to maintain critical smoke detection during emergency configs. So the discrete red SMOKE legend inside the AVNCS SMOKE pushbutton is driven by the active detection look/FWS output. Because of this circuit is hosted on the ESS DC the light stays energized. This helps the crew see the persisting condition after shutting down engines on the ground.

Hope this helps.

Kind regards,

Luis B.

Appreciate the detailed feedback, will log for the team!

Thank you!