Originally Posted by
andrasz
@aussiepax: read...think...write... in that order
@Ian W: A severe fire needs two things - an ignition source, but more importantly a volatile fuel that is able to propagate the fire in a rapid way. There is no good flammable material in the galley, especially in the food cart. The various plastics burn slowly, especially in the thin cabin athmosphere at FL370. In another life I conduct expeditions to remote areas where standard practice is to burn any combustible trash, remove all other. I know how difficult and time consuming it is to burn plastic garbage. It requires a liberal dousing of diesel for it to properly catch fire, and without wind the flames die repeatedly. As all catering and cabin materials are made of certified (relatively) fire retardant materials, I find it a bit hard to envision an accessible fire on board strong enough that it cannot be put out with the extinguishers. With SR111 the problem was that the fire was inaccessible, and the severity was not recognized until too late. Similarly with the two 74F accidents, the crew had no access to the fire location.
There presumably was no flammable material in Abdulmutallab's underpants or the cabin of NW253 yet the IED he had there caused a fire in the cabin wall that had to be put out. The bottom trays of many meal carts are also full of plastic miniature bottles of spirits. So 'imagine' a muted explosion (i.e. more fire than explosion) that blows down and forward from the bottom of a cart into the avionics bay and rear wall of the cockpit. Now get to that area with your fire extinguisher.
Chemical and electrical fires are significantly different than burning trash.