On all Boeing twins, the flight deck is the only area that receives air directly from its respective pack (L). While there is recirculated air in the overall system, the plenum pressure is such that only air from the pack goes to the flight deck outlets. Therefore, if there is an abnormal smell emanating from the outlets up front, we may (uncharacteristically) isolate the LEFT pack first.
Smoke events generally require the same steps on most aircraft. Roughly we: de-energize non-essential electrical loads and isolate electrical busses, switch RECIRCULATION FANS OFF, then, if the source is not pinpointed by crew, the next steps are to: ISOLATE BLEED sources, RIGHT PACK OFF, wait to see if air clears. If no change, R PACK ON, then LEFT PACK OFF and wait and see if there's improvement.
The next stage is smoke removal which involves configuring the aircraft equipment cooling and pressurization outflow valves for maximum air exchange. The goal is having all of the above accomplished within 5-6 minutes, if possible.
Last edited by vapilot2004; 20th May 2018 at 01:07.