I personally do not see a 3+3 narrowbody doing well below 200 seats against a modern 2+3 like the A220 due to the higher OEW, though as you approach 200 seats, the OEW of the 2+3 probably starts to approach that of a 3+3.
I'm not so sure a 3+3 would be that much heavier than a 3+2 in the 170-200 single class capacity. What seems to distort people perception somewhat is that people see the lack of success of the A319NEO for instance which has been hit hardest by the upgrade to the NEO. That thing is plain just too capable for the capacity and the missions that it is intended to fly. If however a single 3+3 fuselage cross section were to be offered in two different MTOW designs (wings, wingbox, landing gear etc.). The smaller of the two could be made significantly lighter than the MAX and the NEO (which have grown overly capable for the required missions) and the smaller one would not be too far off.
I'm not an Aviation engineer so I couldn't do any useful calculation, but I suspects the result would be fairly close between the 3+2 and the 3+3.
I'll list a few arguments for sharing the same 3+3 cross section between the high and low MTOW variant:
1 A 3+2 variant would just be a A220 copy, which is technically very well equipped for it's missions
2 A shared cross sections would have more synergies in both R&D and on the assembly line
3 By starting with the smaller variant in 3+3 the higher MTOW 3+3 would have a better base to start from and better economics of scale against the A320XLR with R&D and a very much optimized production infrastructure. Without this starting point the higher MTOW 3+3 would have a very though time against the A321XLR and possible future variants.
Airbus can't possible produce enough narrowbodies on it's own. It would have to increase production rates to insensible levels. That's Boeing's advantage. It's not to bad if the A321XLR takes a large part market for a few year (even if it's a higher margin market). Say Airbus would have a 75 to 25 market share around the A321XLR's market, if Boeing has a 65-35 market share in the sub 200 single class market. Sure it's not ideal but once they launch the higher MTOW version of the 3+3 cross section 50-50 will be restored or probably.s even better
Last edited by Taxi645
on Wed Feb 12, 2020 7:32 pm, edited 1 time in total.
Innovation is seeing opportunity before obstacle.