Also bad for fuel economy (and/or take a hit on cargo/pax/luggage carrying capacity): You have to take off with all that fuel even though you only need X / hr. Increased weight = more flying at a lower altitude (+ air resistance) until the fuel burn makes it safe to fly higher.
On shorter flights, you still have the weight impact from that empty tank and its infra. If they had to make a bump out on the fuselage, you have a permanent aerodynamics hit.
It's like permanently attaching a cargo carrier to your vehicle to carry more fuel. Fewer fuel stops, but more burn per mile. Can make sense in some situations.
The study of breaking up long-haul flights for reduced fuel burn is usually called: "Intermediate Stop Operations"
On shorter flights, you still have the weight impact from that empty tank and its infra. If they had to make a bump out on the fuselage, you have a permanent aerodynamics hit.
It's like permanently attaching a cargo carrier to your vehicle to carry more fuel. Fewer fuel stops, but more burn per mile. Can make sense in some situations.
The study of breaking up long-haul flights for reduced fuel burn is usually called: "Intermediate Stop Operations"