Originally Posted by
Often1
This was likely a system failure. The potable tanks and the chemical fluid for the loos are not the same and operate on totally different systems (for fairly obvious reasons). Thus, unlikely the aircraft ran out in the sense that the supply was used up.
While I haven’t operated the A380, this isn’t the case on the 787. The potable water system provides water to the toilets and sinks as well as all galley systems. I’d be surprised if the A380 is different to be honest, but I’m happy to be informed otherwise. Chemical toilets haven’t been used on commercial jet aircraft since the likes of the 737 Classics and 757s.