With its 50th 787 now in final assembly and its production rate accelerating to 2.5 aircraft per month, Boeing's suppliers have begun early production of the components that will go on to form ZB001, the first 787-9.
"We're at the front end of some of the component build-ups," said 787 programme vice-president Scott Fancher, speaking generally of the -9's progress.
Boeing disclosed on 26 October the first 787-9 is now due to launch customer Air New Zealand in early 2014, slipping the previously announced 2013 delivery date.
Boeing plans to introduce new single-piece flight deck window frame for the 787-9 designed by Sprit AeroSystems, which aims to lighten the aircraft by 100lbs and remove approximately 200 fasteners from the flight deck structure.
The first test specimen and early production articles have already been fabricated and delivered to Spirit, said programme sources, including those for the first 787-9, which is now expected to be the 138th 787 built.
The 787-8's flight deck windows are based on four separate structural pieces for each sill, whereas the new -9 design provides two single-piece structures covering each side of the flight deck.
Fancher said Alenia Aeronautica and Kawasaki Heavy Industries, responsible for the stretches of section 46 and 43 of the fuselage respectively, are currently in pre-production verification of tooling required for the two 305cm (120in) barrel extensions.
The new flight deck window frames are another in a series of growing structural differences between the -8 and -9. Fancher said evaluations are taking place on a case-by-case basis to determine if the -9's design enhancements will flow back to the smaller -8.
"While the airplanes are very similar, they're different enough that you need to understand the unintended consequences of making a change," said Fancher. He pointed out the investment must also be justified by a reduction in overall recurring cost.
Fancher declined to confirm if hybrid laminar flow control (HLFC) technology will be included on the -9 or fed back into the -8, following evaluations on 787 test aircraft ZA003 in June.
Decisions on various higher risk technologies, said Fancher, will be made on a rolling basis during the third and fourth quarter of 2012, though programme planning has kept such decisions off the "critical path" for the derivative's development.