FlyinCroc sir,
Agree.
You need an oxidising agent (usually O2 from the air) to go with the reducing agent (hydrocarbons various) before you can get a combustion reaction - as well as the activation energy having been exceeded by the spark from the faulty wiring.
As there was no inerting and the tanks are vented to air, its simply an input output calculation as to whether or how much O2 is present.
My money is on very very limited amounts of O2 being there - the Vp of Jet AI being > the diffusion inwards of the air.
In Calcutta no chance - paradoxically the higher the ambient the safer the "empty" tank.
Now what was the temperature profile for TWA800 ..........
Yes we could do the sums but this is so far off thread that I confidently expect the mods to intervene ...........
CW