A320 Fuel L + R Wing Tk Lo Lvl
Hi, What's the definition of "useable fuel"?
The Low Fuel contents ECAM procedure guides the crew to select the Fuel X Feed Valve "Off" (Closed). If single engine, this would isolate about 700 kgs fuel in the other wing tank and there is no mention in FCOM or QRH to ignore this ECAM.
So despite the FOB showing 1400 kgs, if single engine you would only have 700 kgs available to feed your good engine.
How do we stand legally?