@ silverstrata
a. Heat damage in the cockpit area is only on the outside. The co-pilots chair shows no burn mark, the carpet on the floor shows no burn marks, the business class seats we have seen show now burn-marks. The overhead bins we have seen show no burn marks. So no evidence for secondary fires inside the aircraft, not even in the cockpit
b. The tail section of the aircraft broke up at lower altitude, proof for this is distribution close to main impact point. Tail section parts show no burn marks at all. The tail section, up to door 3 right shows no external or internal burn marks. The crew rest bunks, close to the center fuel tanks show no burn marks. Do I need to continue? Engine fire is not unlikely, but this can also be caused by sharpnel alone.
Further, there is no flame or smoke visible in the sky on the only video that started before the impact. Black clouds only started after explosion when the plane hit the ground.
There was only a fireball from the explosion of the missile, and that's it. No resulting fire afterwards, not traces of fire on the outside. Shrapnel could have penetrated the wings and the engines, but not resulting into fire.