Boeing's progressive refinement of the design for the stretched -9 version of its 787 widebody is revealing a Dreamliner variant that is similar to the larger 777-200ER.

While the seating gap between the two aircraft is roughly two rows of nine-abreast seating, the two aircraft have nearly identical cabin lengths, just 59cm (23in) apart. Under the floor, the 787-9 sports a 70.5m3 (2,485ft3) identical forward cargo hold volume, while the rear hold is larger than the 777-200ER's, at 72.5m3.

Dreamliner launch customer All Nippon Airways converted 15 of its 55 787 orders to the larger -9, citing the aircraft's ability to carry about 400 passengers in a single-class domestic short-haul configuration. That layout nearly matches the 16 418-seat 777-200s that will have an average age of roughly 15 years by the time the first 787-9 is delivered to Air New Zealand in 2013.

In a long-haul configuration, United Airlines' future fleet planning for its 787-9 order, held by Continental, boasts a 20% relative trip cost improvement and 10% improvement in cost per air seat kilometre compared with the carrier's 777-200ERs.

Source: Flight International