Originally Posted by
Mesabah
The main issue for building a narrowbody is production rate. They have to fly off the assembly line in huge numbers. Right now that means the 737 and A320 are here to stay for at least the next 50 years. However, Boeing is going to be at such a competitive disadvantage in 10 years with the 73, that they are better off exiting the narrowbody business, and only building widebodies, while letting Embraer deal with less than 200 seat aircraft.
Boeing (Airbus) might well have to startup a new, separate production line for a new NB. That line would get things going on the new model, and then the existing 73 (320) lines would transition to the new model as the old one phased out. That's a management project,, not really a show-stopper.
Most of the global airline fleet will HAVE to be drastically more Eco-friendly (if not lower cost) by 2050. That means they need the new tech ready by 2030, for service entry around 2035. What's going to be hard is doing new designs to cover all fleet sizes around the same time... probably going to need .gov help on that. Might be able to drag out the timeline by using bio-fuel (very low carbon footprint), since that can be and is used in current jets at 50% or greater mix with jet A. But the bio-fuel industry needs to grow by several orders of magnitude to provide the needed quantity... actually more than several orders of magnitude.