[Lower Deck]

I’ll repeat the gist of a comment I posted on FR years ago: there is no way in hell that aircraft departed for a transatlantic flight with an empty center fuel tank.

Sure they would. The distance between New York and Paris is about 3600 miles. A 747-100 fully fueled can fly 6100 miles. The airplane would carry enough fuel to make the trip with a safety margin but it's not going to haul fuel it doesn't need.

[Orbiter]

I’ll see if I can drum up Jet-A costs both in the US and other planned stops for TWA800 and run a CBA for topping the tanks before hopping the pond.