From what I saw last night, it showed the actual aircraft had a 75ft section rebuilt from the million pieces of debris they recovered from the sea bed.
The evidence showed that there had definately been an explosion in the fuel tank, as the main supports had damage as a result of a support beam being thrust forward in the impact.
They couldnt itentify the reason why such an explosion would occur, and carried out tests on Jet A (Kerosene) to see how they could make it ignite. They discovered that ignition was possible when oxygen was starved. The 747 has wing vents which draw out the air as the atmospheric pressure changes on ascent.
In order for the fuel to produce vapour, it would need to be very hot, and because a passenger was late, and the ground temperature was extreme, they had an a/c full of passengers in sweltering conditions.
The air con was switched on (and is located directly beneath the centre fuel tank) which led to the heating of the fuel. Because the tank is designed to absorb heat, this should have been safe. However, there was only 50 gallons of fuel in this tank, which therefore led to it heating rapidly and producing the vapour required to be combustable.
Further to this, the voice recorder identified the pilot commenting on a fuel guage which was showing bizzare readings.
The reason this occured because the normally low voltage wiring to the fuel flow indicator in the tank had been short circuited because the loom was damaged, causing greater voltage in the fuel wires.
Finally, the design of the contacts is such that does not permit a spark, however, they did not realise that carbon deposits built up when fuel and voltage came into contact, thus causing a spark.
The forward section of the a/c split off after the support beams were forced in the explosion, and the fusilage ripped 360 degrees from the front of the wings.
This plummeted to the ground, whilst the rear section headed high into the sky until it stalled, inverted and plummeted towards the sea at 400mph - causing the wing tips to break, fuel ignite, and turn into a fireball.
This would have been a very frightening death for the people on board.
They said that older 747's (25 years+) still flying which hadnt had wiring modifications where still a risk. There are 100 such a/c still in use.
Hope this is a good detailed decription of what happened!