Much more is in the new plane ingredients than first suspected. Timing of an 797 announcement is more of timing when Boeing will rewrite its airplane family line up. The Max has become Boeing's odd duck on the pond. It has made almost every conceivable change in keeping with its family commonality theme. The 777X will be built on 787 technology. The 797 will be built on 787 technology as well. A new clean sheet 737 design for 2030 will be built on 797 technology.
It was long ago decided the 737 was too small of a frame to be efficiently made out of plastic body. A lot has happened since that conclusion and a lot more will happen during the next twelve years before Boeing can get its arms around the single aisle model, which Airbus currently has stolen the march over Boeing in the last decade. Airbus has made some mistakes with its single aisle strategy. Boeing has made more single aisle strategic mistakes.
The big error Airbus made was to sell every customer an A320 without regard to its mismanaged backlog. Some customers will be long gone before it could even get an A320 NEO delivered. Airbus will have to increase its single aisle production capacity over the next few years. It will have to put the A-380 to bed before it can consider a new clean sheet single aisle version in the 2030's. It would rather see what Boeing will do with a 797 design before weighing in on any new clean sheet designs
On the other hand, Boeing neglected the single aisle segment during its first wide body building program starting in 2005. The 757 was turned lose from Boeing while Airbus stole potential Boeing customers with its A321. Boeing was disorganized from the leadership level on down. A lot of Boeing changes occurred during the first five years of the millennium at a critical moment. Now Airbus is seeing a lot of corporate changes going on within its world and is weaken for applying aggressive action with new clean sheet designs until 2025. Boeing will have a new 797 flying by 2025. The 777X will be old hat in its line-up by then. The only unfinished Boeing Business remains for the 737.
The problem for the 737 and the Max program was composites were not efficient for a smaller bodied aircraft during 2012. It would not improve single aisle performance enough for the expense of using it in its frame. By 2025 there will be even lighter and stronger composites available offered to the 797 program which a 737 type could also use efficiently for its own remake. The problem for all single aisle airplanes are they are too narrow for big passengers. Today, single aisle airplanes are built for 5'7" passengers weighing at most 150 pounds. Air travel needs to adjust to the human reality.
The latest 797 proposal floated is a flying oval body made from composite material. A 737 design in 2030 could use lessons learned from the 797 design making the clean sheet 737 having a wider area for passenger going across. The landing gear of course would give it a high enough stance for larger engine circumference and more jet power efficiency. The design engineers at Boeing are all scrambling for the 797 golden BB design hitting its target in this high flying world. The 797 is the key for a future 737. It is taking Boeing a long time for the 797 announcement because it is actually in the hunt for two airplane types that will mutually synergise each other in the market place. The big problem is for cargo area which is reduced using a flying oval body. That problem has five more years of time for innovative body design and solving any space issues.
The 737 redesign is waiting for cheaper, stronger and lighter reinforced plastic body materials for 160-200 passengers. The 797 will fill the gap above 200 seats. Current process maturity and ongoing innovation is close to becoming the core elements for a new 737 clean sheet design from the 797 project.