Tray Surfer has it with the ice-bins! It's important that the ice isalso submerged in water ,to maximise heat transfer. Water will not extinguish a lithium fire, neither will oxygen starvation.....this is important.

A lithium battery fire is self-sustaining it has it's own oxygen supply.

Water and ice will cool it , hopefully you can get it cild-enough to stop the thermal-runaway (works a bit like underground coal-mine or peat-fires...both burn quite happily without external oxygen.

I wondered if a Co2 extinguisher, inverted , so it sprays liquid Co2 onto a battery, may well be very effective at instantlt freezing a burning battery.



Reverting to yhe original scenario......if the terrain is that hostile, you're a goner anyway....keep 'er flying and look on the map for a divert...at least, if there is a fire and you do ultimately lose control, your body will be recovered quicker.:}

I have had a situation where main deck fire warning. Luckily, we had an extra crew member who could don a PBE ( 744 cargo) and check it out. We were 2 hours away from land so a water landing would have been attempted if the fire was uncontrollable. Both UPS and Asiana must wish they landed immediately. Lithium is too dangerous.

Fortunately, most cargo fires occur during the early part of a flight, though maybe not soon enough (before I show up to the plane for my preference), so running back to the departure airport may be the choice (a lot of good it did UPS and Asiana admittedly). As for ditching, I spent a long time talking to a gentleman that had Boeing Clipper time (flying boxes after WWII). He said that they considered putting down on the open ocean largely unsurvivable, obviously with a lot of caveats. Certainly, I would attempt to verify I had a fire before using ocean water to put it out. On the other hand, the only way a ditching has a chance of being survivable is to land under control, so its a quick decision.

On another note, I am told that Li-ion fires are quite toxic, so egressing after ditching may be rather fraught as well.

In any case, management will have you off of payroll by touchdown, and the NTSB- or whoever- are sure it was pilot error.