Boeing executives say the 787-9 is still on schedule and under-weight, but the 787-10 needs a "little more work" before the company is authorised to offer the aircraft to customers.
Pat Shanahan, senior vice president of airplane programmes, and Larry Loftis, vice president and general manager of the 787, reassured investors in a teleconference that confidence is growing in the maturity of the supply chain even as the production rate doubles twice within two years and new variants are proposed.
Shanahan pointed to the progress on the development and production of the 787-9, which is due to enter flight test in 2013 and enter service in early 2014.
"If you go to [forward fuselage supplier Kawasaki Heavy Industries], you'll find three units in production, the spar is being built at [Mitsubishi Heavy Industries], and major assembly will start in January," Shanahan says. "If you look at the real indicators of introducing the -9 into the production system, that looks very good. No engineering issues have popped up so far."
Breakdowns in the 787-8 supply chain were partly blamed for the type's three-year delay to service entry. The delays created a bottle-neck of dozens of completed aircraft that required rework and change incorporation before they could be delivered to customers. Boeing will not be able to clear out the inventory back-up until early 2015, Shanahan says.
But Boeing began delivering aircraft straight off the production line and bypassing the change incorporation line in early June, and it continues to stabilise. Boeing has already delivered 35 787s through the first 11 months of the year, meeting the low-end of the company's guidance of 35 to 42 aircraft deliveries in 2012.
While Boeing still struggles to meet the weight specification on the 787-8, the stretched variant has not been affected by the same problem.
"The weight of the airplane has been very stable through the whole programme," Loftis says. Shanahan adds: "We improved it a couple hundred pounds."
Meanwhile, Boeing has been able to redeploy more staffing resources on efforts to improve the profitability of the overall programme as the 787-9 moves from engineering into production, Shanahan says.
Boeing still will not commit to an entry in service date for the double-stretched 787-10, which will feature more seats and shorter range than either of its sister aircraft.
"The market will tell us really when that is, but really we're looking at the back end of this decade," Loftis says.
Major Boeing customers were summoned to Seattle in late October and early November for briefings on the 787-10 performance. The briefings were received with public praise from Air Lease founder Steven Udvar-Hazy, but he still asked Boeing to extend the range by about 100nm to reach the 7,000nm mark. Other airline customers have asked Boeing to emphasise more seats over range.