Landing with 5 tonnes total and 3 tonnes in tank 2 leaves 2 tonnes in the other main tanks.
2 tonnes is the Minimum Desired Landing Fuel in my manual
less go around fuel.
Mimimum fuel in a tank is about 0.23 tonnes; so, I would be seriously disappointed that the override pumps failed to deliver that last 3.77 tonnes to the working engines.
The other nasty bit is that you discover this defect rather late in the game
Only in the inboard engine failure case are the override pumps called upon to empty tank 2 or 3. All engine operation does not call upon the 2/3 override pumps to take these tanks down so low.
And I do not see in my manuals or checklists a higher unuseable fuel figure for tanks 2/3 when they're not directly feeding their engine
