Originally Posted by
Eclan
You could possibly argue they were so worked up over failures they never got around to LNAVing it.
Yes, it would be very chaotic in the cockpit following an oxygen bottle rupture in the electronics bay. Many things would be overlooked.
The lack of Flight ID, but with the AES ID present at the 1825:27 SATCOM logon is the clue. What is the point of just deleting the Flight ID portion, it doesn’t hide the identity of the aircraft. Since there wasn’t a log off recorded by the GES, then the Flight ID was not manually cleared via the MCDU. It requires the AIMS to be depowered or a power reset of the FMC. So possibilities include someone going down into the MEC and pulling circuit breakers (highly unlikely), or there has been an FMC failure and software reset to the other FMC. Thus, there will be a period where the aircraft doesn’t have LNAV capability. Given that the aircraft was observed on primary radar to NOT be flying via LNAV between IGARI and Penang, then it’s possible that during this diversion, LNAV was not available, forcing the crew to fly on heading or manually. It’s not until west of Penang where primary radar shows the aircraft flying via waypoints ie LNAV is now available.