HONOLULU (HawaiiNewsNow) - After years of strong aircraft orders for both Boeing and Airbus, as shown by this graph, sales have fallen off. Delta announced this week it is postponing taking delivery on some jumbo jetliners it ordered from Boeing. Delta said it re-evaluated its expansion plans based on jet fuel prices. That's what's driving the overall trend, too. When fuel is cheap, airlines expand faster and try new routes. When fuel rises, carriers become more careful, and are quicker to drop a new route that is taking time to find its public.