King5 then came out with it's own story, citing Scott.
I have to say I do not believe we will see a clean-sheet aircraft as a replacement for the B757 - at least not in the time frame Scott is mentioning. He sees a window for EIS opening in 2025, with Boeing probably being the first mover.
- Business Case for B737MAX and A320neo. The A320neo will delivered from October 2015 onwards, the B737MAX roughly two years later (July 2017 as it looks right now). If a B757 replacement would be available in 2025, announced to the public by 2020, the B737MAX-9 would be dead by then. The B757 replacement aircraft (B757R) would be more economical on all missions - not just on the longer ones. In other words: if the -MAX9 would be more economical on shorter missions, there would be no justification for launching the B757R. In the end this is the reason why we are waiting for the the re-engined versions of the narrowbodies today instead of clean-sheet aircraft: it was not possible to develop an aircraft with 20% lower cash operating cost with an tube-and-wing aircraft. A revolutionary concept, say a blended wing body with open rotors was conceived as a risk that was too high (additionally it is questionable how you want to seat the passengers in such an aircraft, how you want to handle boarding and de-boarding, how airport layouts would have to change etc., etc.). Now, with the re-engined aircraft, the hurdle to achieve a significant improvement is even higher. But if Boeing (or Airbus - or anyone else) would be able to do so, there would be no need for the largest versions of today's narrowbody lines anymore. The A321 and the B737MAX-9 would be dead immediately for a relatively small portion of the narrowbody market (or would the B757R be a small widebody?).
- The engine OEM's and their Business Case(s): a B757R would need more thrust than the A321 and the B737MAX-9, even if it would be a complete carbon fibre airliner. So the PW1100G and the LEAP-1A would not fit. They could get a thrust increase, of course, but by how much. The engine competition between CFM, PW and RR, at least for the A320neo, was fierce and every fraction of SFC counted, so we can assume that the engine maker came up with the smallest possible engine core, driving up core temperatures and bypass ratio and thus thermal and propulsive efficiency, implying the most advanced cooling technology and materials . To increase thrust, even more sophisticated cooling and materials are needed. maybe CFM can borrow some more of these from the GE9X in a few years. That would enable more thrust with the same efficiency or a better SFC (through less cooling air usage) at the same thrust, showing the way for a PIP package for the LEAP-1A/B/C (and of course we can expect that PW is also looking at advanced cooling and materials). But it would not enhance thrust capabilities and SFC at the same time. To do that both engine makers (or RR of course) would have to invest in a complete new engine with a new core and possibly a complete new cycle philosophy. This would mean to take another $1 billion, after investing a lot of money in the engine line-up we currently see in development. The Business Case, for which the amount of spare parts sold is so critical, would never turn from red to black for the current LEAP and PW1000G engines, as they would depreciate in value and would be replaced too early and too fast.
- another stretch (adding a -MAX10 and a A322)
- a new, larger wing for the then two largest members of the family
- maybe using AlLi for the fuselage to save weight
- an engine thrust increase as described above
Of course, 2025 is a long time to ago and there could happen a lot - so let's wait for 2020 and see what aircraft will be announced...