I was travelling as a passenger on a 747-8. Around 5 minutes after we left the gate, the captain said we had to return to the gate due to "technical issues with the air-conditioning". The mechanic troubleshot the problem for around 45 minutes, during which the air-conditioning was completely off (but the fans were still running), and it was getting hotter by every minute. Finally, the announcement came and told us the problem could not be repaired on spot. We had to switch plane to continue the journey.
Most airliners have two "packs": left and right. They provide air pressurization and temperature control to the cabin.
- Is it feasible to complete an entire flight with one pack inoperative?
- If #1 is true, is it legal to takeoff with one pack known to be inoperative? (i.e. does the Minimum Equipment List allow this?)
- If one pack fails shortly after takeoff, would the pilot turn around and land, or continue to the destination?
- What alert message did the pilots likely got in their cockpit in my case?