While I commend the idea, there are - as indicated above - heaps of problems with it.
-Water is heavy. Foam is made using (mainly) water. The amounts needed would make it prohibitive.
-Even the waste water/fluid on board would represent a drop in the ocean when it comes to using it to create an even slightly useful amount of foam.
-Most emergency (landing gear problem) landings have a successful outcome, anyway.
-Where foam is used to cover the runway touch down point, there is a small window of usefulness to put the aircraft on it after it's been applied. If a fire does develop during the landing, in situations where this has been done, there will be nothing available for five minutes or so, to extinguish it; all the rescue tenders will be refilling their water tanks, having exhausted them by foaming the runway. (It really does take a lot of water to do this. And we're not even talking the entire runway - just the touchdown zone.) For these sorts of reasons, foaming of the runway is not an available option, mostly, even if the pilot requests it.
-Modern foam consists of AFFF. It's extremely good for putting a fire out; pretty much useless as a prophylactic. (It's also very corrosive to aluminium.)
Is it too late to change project ideas? Development of lightweight cabin furnishings that do not support combustion, and do not emit such toxic smoke as the present ones when held to a flame would probably be a useful endeavour. (Smoke is the big incapacitator following a survivable crash where fire starts. And it's quick.)
Another idea might be a heat - proof cargo container with an automatic and highly effective heat transfer unit, so that if the, say, laptop cargo burns, the flames (a) will not burn through the container, and (b) the excess heat (sooner or later the container would get hot enough to damage the surrounding structure) is somehow able to be vented outside.
Either of those ideas might actually have some uptake in the real world.
[edit] Or another pet hate of mine: Overhead lockers usually have several dozen litres of duty free alcohol in them. It seems no regulator is interested in actually doing something about this slightly thorny issue - which is only an issue if there's a crash. (Korean Airlines at Guam was a classic. Booze rained down from the overheads, and ignited. Seems it had a pretty big effect on survival times following the crash/contributed to quite a few deaths.)
-Design a shock-proof and liquid-proof container within each overhead for containment of bottles of spirits in the event of a prang. Needs to be light, cheap, not voluminous, easy to use, and do the job. Good luck.
Last edited by Tarq57; 12th Mar 2014 at 22:19.