Airfoilmod. How do TWO separate, isolated and independently controlled systems exhibit virtually identical (Failure) behaviour simultaneously.
Good morning.
I quoted your rhetorical question since I believe the answer lies in something that is COMMON to the two separate, isolated and independently controlled systems.
ETOPS, from my extremely limited knowledge of the subject, appears to be working well, but we should not overlook that fact that certain aspects of the (duplicated) installation are COMMON.
It appears that we may not be looking at something having gone wrong, but rather a situation where the interface between
FUEL, ENVIRONMENT, DESIGN, STANDARDS and PROCEDURES has created an UNFORSEEN situation / scenario.