Originally Posted by
archae86
Whle I understand the recording function of the forward recorder would continue on the local battery, would not a very large majority of recorded data parameters have ceased being supplied to the recorder immediately on loss of main-bus power? Do we have any general idea of which ones? And between the RAT and the attempted relight of the engines, is there an identifiable point in the sequence in which power source for most of the data parameter sources would have resumed?
Yes, any information that comes from LRUs that are not on the battery buss would be lost when main bus power is lost.
I'm not familiar with the specifics of the 787 avionics, but the following are required for continued safe flight and landing, and are on the battery:
Left EICAS
Left PFD
One ADIRU (likely the left).
At least one level of the FBW system