So, Amicus, if there is a point heat source (like say an electrical short or a spontaneous ELT battery fire) that applies 581F to the inside top of the fuselage just ahead of the tail fin, what are you suggesting happens?
1. Toxic smoke & fumes from hot resin start to fill the cabin? OK, so presumably there's a procedure for that...
2. The structure around the point heat source is compromised... OK, not great, going to cost a fortune to fix in due course, but one small patch of structural weakness does not translate to a crash...
3. Will the skin of the aircraft actually catch fire? Will it burn, will it self-sustain in a 200mph wind blast? Can somebody say with the confidence born of having evidence, that it won't happen?