The B757 successor discussion

Yesterday MTU’s COO Rainer Martens revealed during the annual results presentation that there is a plan to upgrade the PW1100G engine for the A320neo with another 3% SFC jump by 2019. On a side note, as the turbo machinery of the PW1100G and the PW1400G are identical,  the MS-21 will also benefit from that as I think that P&W and their partners will not start building  two different engines.
But what does that mean in a broader context?
Firstly, we can be very sure that a similar PIP (Performance Improvement Package) will also be worked out for the LEAP-1A (and the LEAP-1C destined for the COMAC C919, as this engine has the same turbo machinery as well). Another report on a german website cites MTU’s Martens that the 3% improvement are agreed with Airbus so we expect that there is a corresponding  agreement between Airbus and CFM to lower SFC around 2019/20. As the GE9X goes into service by that time frame we can expect a lot of technology transfer from the GE9X to the LEAP-1A – and subsequently to the LEAP-1B for the B737MAX.
Secondly, this makes the business case for any A320neo and B737MAX successor harder. This is why I do not believe in a B757 successor in the time frame that was discussed by Scott Hamilton and others lately. At least not in the sense of a purpose build aircraft. Here is why:

·         The 3% lower SFC for the A321neo (and probably sooner or later also for the B737MAX-9) leads to 100+nm more range, bringing these two aircraft even closer to the capabilities of the B757 today.

·         As of today the A321ceo can do about 95% of all routes flown by the B757 today. And the A321neo can only NOT do five city pairs flown by the B757 today (I go that verbally from Airbus). 

Add the 100 extra miles coming out of the engine improvement and what is left? Maybe three routes, maybe four routes, maybe still all five. Add some improvements to the airframe and what is left then…?
I am  sure there is no business case left then for building a standalone aircraft with the capabilities of the B757. But also as part of a new family of narrowbodies, aka the A30X and the B797, there is no real need to compromise the efficiency of the whole family with a wing that is large enough to cover distances more than what the A320neo/B737MAX families will do. Otherwise Airbus and Boeing could lose market share against a Bombardier CS500 and a forthcoming Embraer small narrowbody  which are designed for ranges less than 3000nm.
But I do not see these new breeds coming a of 2025 as James N. Krebs postulated in this very interesting guest column at Leeham News. But if we see a further 3% improvement from the engines at the end of the decade, how should there be another jump of 20% in fuel burn in 2025? The technology for an aircraft with an EIS must be defined by 2018/19. With a regular tube-and-wing aircraft I cannot see a jump more than 10% from the airframe - if designed for the same range (more range: less efficiency gain for shorter routes). If we take 1% efficiency gain for every year from improved engine design (and that seems optimistic as it gets harder and harder), we get a maximum of 15% versus neo/MAX. Not taken into account that there can still be something done to the existing aircraft as well like building the fuselage from AlLi or enhancing the wing. The business case for an all new aircraft then disappears in my eyes. But I am not a bean counter…err… accountant.
Another question is if someone will do something in the sector left by the likes of the A300-600R and the B767-300(non ER): 250-300 seats, 4000nm max range. Being hinted to think about that, as can be read in the Pudget Sound article. I do not count that as a B757 successor and  I do not know if there is a business case for that but Lufthansa always cried for “people mover” like that.