DoctorVenkman wrote:What sort of mechanical failure could cause a midair explosion like that? The only thing I can think of is an uncontained engine failure piercing and igniting the fuel tanks. Is there any other known issue that could have caused this?
A puncture of the fuel tanks isn't going to result in an explosion unless the fuel tank is mostly empty and already is in the explosive mixture present. That means the tank is in the 30°C to 45°C temperature range. Colder doesn't explode from a lack of fuel fumes and hotter doesn't explode from a lack of air (and the oxygen in it). Usually any aircraft tank is colder than that at all times except on hot days with long times on the ground.
TWA800 was the perfect storm. The center tank was empty because it isn't needed for transatlantic flight. It was a hot summer day, so the little fuel left heated up in the sun and stayed hot. Lacking those conditions, a bunch of shrapnel holes (bomb or engine caused) doesn't result in a catastrophic failure of the aircraft. It means a bunch of fuel leaks and that can cause a fire, and maybe even a subsequent explosion, but not one right away.