The much-anticipated emergence of the 787-10X comes as Boeing wrestles with defining the configuration of its next major derivative program, the re-winged, re-engined 777X. Compared to the relatively straightforward double-stretch of the 787-10X, the development of a pair of larger successors to the 777-200LR/300ER for possible entry-into-service in 2019 is a far greater gamble in terms of cost, technology and marketing tactics.

Coming on top of the likely launch of the 787-10X, the timing of the next 777 development is pivotal to Boeing’s commercial strategy as the airframer weighs the threat of the upcoming Airbus A350 for the end of this decade and beyond. However, the size of the 787-10X is itself now thought to be playing a role in the outcome of Boeing’s 777X deliberations as it could feasibly cannibalize at least part of the intended market of the 777-8X, the smaller of the proposed 777X twins. Other resource-related factors playing heavily into the launch decision include Boeing’s already busy product-development plate, which is full with the on-going 737 MAX, 787-9 and KC-46A tanker programs, as well as the ramp-up of its production lines at both Everett and Renton, Wash.

It also comes as Boeing continues to accelerate 787-8 deliveries toward its year-end target of 35-42. Some 30 aircraft have been delivered to date, with as many as 18 more believed to be at or close to delivery readiness.