JD-EE
Vaguely, I should do a bit more homework to brush up on the basics. "Tumble" is the physical analogue (from old gyroscopes) I am trying to use to describe the function becoming unreliable, based perhaps on accelerometers going wrong, but I won't comment further as I think the laser ring gyro has been adapted due in part to its higher reliability. (Fault tolerance).
As to lost calibration, causes of that would, it seem, remain in the electrical, rather than physical motion, domain. Do I understand that correctly?
I'll stop with the wandering off into partial panel wilderness. Sorry, BOAC, for bringing that up again. In the process, I've learned a bit, so maybe not a total loss. Where I think I wandered off was in pondering an ADIRU fault consideration. We have tended to discuss that more on the Air Data side (based on pitot tube / probe issues), rather than IR faults (Inertial Reference) within that system, based on the ACARS messages.
FDR will doubtless be much clearer regarding what was doing which.
That said, there have been (in a general sense) ADIRU faults in the past the pilots had to trouble shoot due to impact on their attitude reference display. The summary I just reviewed again shows crews to had sort them out or handle them via (IIRC a 777 incident) by degrading Auto Pilot funcitons ... perhaps while being in a bit more benign flight environment than T Storm penetration?
Thanks to OK465 for the sim training and unusual attitudes points. Appreciated.
