Originally Posted by Dozy
I think this is the BEA saying that it's impossible to know what the PF was actually seeing, and they don't like having to take it as read that he was seeing the same as the PNF, whose instrument displays were recorded.
Too much reading here. Having a camera showing all the displays and crew actions (postions/attitudes) would be very helpful rather than having to derive something from recorded data which doesn't give any hint about what can NOT be derived. (e.g. was the PNF reading silently the documentation? was he scanning the displays? looking at the PF actions? did they exchange meaningful regards?)
A lot of things needed to understand their actions are lying in cockpit ergonomics and pilot's way to deal with the interface. Most of what would be very helpful to investigation, in this case, is lost without a camera record. About the flight data missing, it seems that it would be better/easier to have them directly recorded rather than filmed.