Originally Posted by
lenscap
One thing the 359 offers: a plane that seats around 275-300 with range to replace the 772s. Once the 276-seat 772s start leaving the fleet, for longer flights United will be left with 252-seat 789s (which I imagine will drop in capacity a bit when Premium Plus is added) and 350-seat 77Ws. If they don't get the 359 (or something comparable), they will have to mostly use 789s as replacements and suffer capacity downgrades in growing markets to Asia (the 787-10 has the capacity but not the range). Will this be enough to add the 359 to the fleet? Time will tell.
The fact that UA did some proving runs on the 78J (e.g. IAD-PEK) suggests that UA may figure that the 78J can adequately cover enough 772 routes that it can take over most of its flying and use the 77W exclusively on the longer-haul 772 routes. That said, UA has not placed any more orders for the 78J - only the 789 so far - so perhaps that’s not quite in the offing / their thinking...yet.