The Sandwich Aéroport is a category defined by its constraints rather than its recipe. It is the sandwich made to be assembled hours ahead, sealed in a wedge of plastic, held in a chilled case, and bought by someone with a boarding pass and no time. The contents are familiar, a baguette or a triangle of pain de mie with ham and cheese, with crudités, with tuna and egg, but the contents are not what defines it. What defines it is that the sandwich has to survive a long wait between the person who made it and the person who eats it, and every choice in it bends to that.
The logic is the logic of refrigerated time. A sandwich that will sit for hours cannot use a fresh-from-the-oven crust, because the crust will go leathery in the cold and soften where the filling touches it; it cannot use a wet tomato against bread, because the bread will absorb the water and turn pale and slack; it cannot rely on a sauce that breaks or a cheese that sweats. So the format compensates: more butter or a fat barrier between bread and any moisture, fillings chosen for how they hold rather than how they peak, bread that trades crust for resilience. The result is a sandwich engineered for stability, not for the short window that makes a counter-made one good. Eaten cold straight from the case, it is competent and even; it was never built to be eaten at its point, because its point is to still be edible long after assembly.
There are no real variations to codify here, only the same compromise applied to different fillings: the chilled jambon-beurre that has lost its crust, the tuna-and-egg that holds up because mayonnaise is stable cold, the crudités version that is only as good as how recently it was packed. The honest read is that this is a constraint, not a cuisine, and it is best understood next to the Casse-Croûte, the snack made from whatever bread was already around. The Sandwich Aéroport belongs with the place-and-occasion sandwiches the catalog groups under Regional Specialty Sandwiches, the named formats that are about where and how a sandwich is eaten as much as what is in it. Its specific contribution is to show what a sandwich becomes when survival, not freshness, is the design goal.