Originally Posted by
Rainier
The 757-300 was a victim of timing in nothing else. The line was shut down immediately after industry contraction from the 9/11 attacks and was also the victim of the merged Boeing-McDonnell Douglas management that focused on Return On Net Assets, which made the Renton factory floor appear expensive. I have been told by those in the know that airlines came back to Boeing after the 757 line had been shut down requesting to purchase more, but by then the decision had been made.
The 757-300 for a long time had the best single-aisle economics, which is why Delta/Northwest used them to replace the DC-10s on their Hawaiian routes, which are the most price competitive in the US. One can see why airlines are asking for a new airplane to fill this niche. Looking back certainly, the continued low fuel prices also played a part in 757-300 orders as it permitted more fuel-inefficient airplanes to continue operating rather than be replaced.
The problem with a 757-300-type replacement is whether the size of the market is sufficient to develop an entire new platform and new engine. With 737Max and A320Neo families offering trans-continental capability, the market for a slightly larger airframe with marginally more range might not be sufficient to drive the per unit costs down low enough to take market share from 737Max/A320Neo airplanes to make the business case work. Rather than use a 757-300 replacement, airlines might just use more frequent 737/A320 flights on the shorter segment to fill the need rather than pay higher acquisition costs for a more fuel efficient narrow body.
I think Airbus could do a bigger A322, trading payload for range. The 101t MTOW A321XLR seems to provide the starting point for a stretch. 3500NM would still be possible with 250 passengers & luggage.