ACARS down before transponder
One of the last ACARS Messages transmitted by AF447 concerned cabin pressure, IIRC external altitude becoming lower than cabin altitude.
It makes me sick thinking about it:
- Turn off ACARS
- Then depressurize
- Wait 12 minutes until cabin emergency O2 is used up
- Turn off transponder
- Zoom climb to what is possible, on topping out there will be less than 1g so it can be somewhat higher than what is in the spec
- now return, over land no cell phone calls will be made