Fault tolerance and Graceful Degradation?
 

Incident: LATAM B773 near Belo Horizonte on Dec 20th 2018, electrical failures, RAT deployed

"On Dec 20th 2018 Brazil's CENIPA (NTSB like) reported electrical failures occurred in cruise flight, which also compromised other aircraft systems. The crew decided to perform a precautionary diversion to Belo Horizonte for an overweight landing. As result the brakes overheated causing the fuse plugs of the tyres to open and the tyres to deflate. There were no injuries, the aircraft sustained minor damage."

https://cimg7.ibsrv.net/gimg/pprune....0fd89a30e8.jpg

The incident electrical page showing all electrical busses without power

"On Dec 22nd 2018 The Aviation Herald learned that the electrical problems started with the failure of the right hand backup generator, as result both transfer and both converter circuit breakers popped leaving all electrical busses unpowered although left and right main generators as well as their generator controls, the APU and the left backup generator remained operative (see ELEC page below, the lines to the L MAIN and R MAIN should be green not white and these symbols should be green, too). As result almost all systems except a few connected to the standby busses lost power, only systems remaining powered are: stand by busses (powering one VHF radio) and emergency lighting, the left inboard and outboard and upper center displays as well as the left CDU remain also powered (according to FCOM via the batteries and/or RAT - with the RAT operating also the right hand - first officer's - displays are being powered)."