educated guess, they get to stop on the ground to refuel. So while they need to travel further, they need to carry less fuel per each hop. There's probably a

educated guess, they get to stop on the ground to refuel. So while they need to travel further, they need to carry less fuel per each hop. There's probably a little bit of effect like the rocket equation going on - the further you are going, the more fuel you need to get there, and the more fuel you need to carry the additional fuel. Stated a different way, fuel requirements vs distance is worse than linear, since fuel itself has weight.