The only thing that was brought up that kind of made me wonder was the fact that both the Swissair and TWA left JFK at 819pm on the same departure on a wednesday. They also said that the Swissair lost coms with ATC in very close proximity to where the TWA flight terminated. Is it posible that there was bad shielding on a wire in the TWA flight and when a burst of EMI radiated it shorted and caused the spark, igniting the hot fuel tank. With that theory the same could be said about the coms on the Swiss fight going out due to poor shielding. This is just all wild speculation and something to ponder. I did find it very interesting that NASA did a study that said that, like you said, there is more EMI at the airport before you leave than on the flight.