Night Fall by Nelson DeMille

center tank only if needed. This flight to Paris had a light passenger and cargo load, and the forecast was for good weather and tailwinds.” He added, “Ironically, if the passenger and cargo load had been heavier, and/or there had been bad weather or headwinds, that tank would have been full of jet A fuel, which is actually difficult to ignite. Fuel
vapors
are volatile. So that fact alone fit the scenario of an electrical short circuit igniting the vapors and causing the kind of explosion that the forensic evidence strongly suggests.”
    “What kind of short circuit? I mean, should I cancel my trip to Bermuda?”
    Mr. Siben didn’t smile at my stupid joke. He said, “There are four plausible and actually proven scenarios. One, a short circuit in the electric wires or motor in the scavenge pump; two, there’s always static electricity; three, there’s the fuel quantity gauges, which are electronic; and four, there are the tank’s electrical conduits. In other words, that big tank over there has electricity in and around it. If the tank was full, a spark could not ignite the jet fuel. But vapors are a different matter.”
    “So you keep saying.”
    “And I’ll keep saying it. It’s the laws of physics, Mr. Corey, which can’t be repealed by theories.”
    “Yeah, but we don’t
know
— ”
    “No, we don’t
know
. But what we
believe
happened was that a wire was frayed and that a short circuit developed somewhere, inside or outside the fuel tank, and that a surge of electric current caused an arcing-a spark-and what started out as a remote possibility-the short circuit and the resulting spark in the one place where it could cause catastrophic consequences-became reality. It’s happened twice before on Boeing aircraft-one time on the ground, so we could see exactly what happened. In this case”-he looked at the 747-“the fumes ignited in midair, and caused an explosion that may or may not have been catastrophic by itself, but that apparently traveled sideways with enough force and heat to actually ignite the fuel in the left wing tank, causing it to explode, which in turn made controlled flight impossible.”
    I asked, “You deduced all this from”-I pointed to the 747-“from that?”
    “Absolutely. All the evidence was there as soon as we determined that the initial explosion occurred in the empty center fuel tank.” He added, “This is borne out somewhat by the eyewitnesses, some of whom reported a small explosion, followed by a huge fireball. These explosive forces caused a shock wave that separated the forward section from the main fuselage. This was also observed by people on the ground.”
    It was interesting, I thought, that the eyewitnesses who saw the separation of the aircraft in flight, which would have been difficult to comprehend, were cited as backup for Theory A, while many of these same witnesses who saw an unmistakable streak of light were discounted. But Mr. Siben was volunteering his time, so I didn’t want to point this out.
    I looked at Kate and asked her, “Are you buying all of this?”
    She hesitated, then replied, “Yes… up to a point. But as Sid can tell you, tests were done on an old 747 on the ground to try to reproduce this sequence of events in a fuel tank, and they couldn’t get an explosion.”
    I looked at Sid and said, “How about that?”
    Mr. Siben replied without a trace of hesitation, “You can’t reproduce conditions on the ground that took place at thirteen thousand feet in a moving aircraft. It was a stupid test.”
    “If you’d gotten an explosion, you wouldn’t think it was stupid.”
    “Yes, I would.”
    The guy was unshakable. I wished I’d had witnesses like this on the stand when I was a cop. I thought of Captain Spruck and asked, “If a kinetic missile had penetrated the aircraft from below, and traveled through the air-conditioning units, and damaged live electrical wires in and around the fuel tank, would that cause the vapors in the center