I'm not a 169 man but I do recall my colleagues saying that there are no booster pumps in the 169 and with the same basic tank design as the 139 there will be unusable fuel in the tank supplying the dead engine.
The laws of physics dictate that if the engine sucks through the crossfeed then in theory both tanks will supply the one live engine. I suspect that those same laws of physics will generate a pressure drop across the crossfeed lines leading to a preferential supply from the most direct tank - the one supplying the live engine.
As the fuel level drops the imbalance will grow until the live engine's supply runs out. This will turn into a big headache because once the engine sucks air it will wrap its hand in. Methinks that hauling that inaccessible fuel (200 litres?) around will become tiresome for it can never be part of your reserves.
The stopwatch is running on how long it will take for the booster pumps or transfer pumps or low-level transfer valve to appear.
Now I will go into work and get beaten up by my 169 buddies.
Aye G.
