The Boeing 777X was supposed to be the low-risk successor to one of the most successful and popular widebody aircraft ever built. Airbus developed a new carbon-fiber fuselage, advanced composite wing, entirely new production techniques, fresh avionics architecture, and a completely new certification program. In other words, the total 777x program cost is substantially higher than the reported accounting charges. The program has even seen an extraordinary step rarely associated with modern commercial aircraft development, which caused outrage among many aviation enthusiasts. Even then, however, the program will remain a remarkable case study in how dramatically the economics of commercial aircraft development can change.