BuzzBox
”Without the valid landing altitude data, the cabin altitude warning message shows at 15,000 feet” - see 777 Training Manual 21-30-00 p 38
Thanks, I hadn't seen that before, despite operating the B777 for almost 10 years. It's included in the Maintenance Training Manual, but apparently it wasn't considered important enough for the FCOM.
If I'm not mistaken, under your scenario the Satcom SDU remains powered throughout and the logon request at 1825:27 is explained by the right HGA coming into view of the satellite as the aircraft turned. If that were the case, how do you explain the abnormal BFO that was recorded for the log-on transmissions from the aircraft? The MH370 Safety Investigation Report concluded that it was most likely due to the power-on drift of the SDU OCXO, which endorsed the investigators' belief that the 1825:27 log-on was preceded by a lengthy power interruption.