Boeing today ended speculation over potential challenges in meeting targeted weights of the 787, acknowledging that its early aircraft will be overweight.
The confirmation from Boeing occurs after Bernstein Research recently released a report estimating that early production 787s could be delivered as much as 8% overweight resulting in a range shortfall of 10-15%, putting the 787's range at 12,800km (6,900nm), well below the advertised ranges of 14,200-15,200km.
Boeing confirms that "early airplanes are heavy and [we] are working hard on implementing weight improvements".
Despite this, the airframer insists that it will "meet mission payload commitments to all customers". Adding that the report's "conclusion on range is inaccurate and the 787-8's range is closer to 8,000nm [14,800km] than 7,000nm".
© Jon Ostrower/Flight International
Boeing already plans to incorporate an initial round of weight savings into its seventh airframe, which is the first production 787, followed by block point changes in aircraft 20 and 100. These will incorporate improvements from the lessons learnt in the flight-test programme, as well as take advantage of design improvements developed for the larger 787-9 variant.
Bernstein also doubts the ability of the production system to meet its goal of producing 10 aircraft a month by the end of 2012, suggesting that at least an additional six months will be needed to reach the ambitious production rate by mid-2013.
"The Tier 1 suppliers have not yet validated their production capacities with the new production technology, and if substantial redesign is needed to reduce weight, it will further complicate a rapid increase in delivery rates," the report notes.
Boeing is maintaining its production forecasts, and stresses it is "fully coordinating with partners on production readiness and the critical design block points changes" to meet the planned ramp-up.
The Bernstein report also describes the manufacturer's plan to complete the 787 flight-test programme, certificate and deliver the first aircraft to Japan's All Nippon Airways in the first quarter of 2010 as "ambitious".
The airframer has reaffirmed its 787 flight test methodology saying the plan is "based upon our experience with the 777 programme".
Boeing explains flight-testing of the 787 will be a 24/7 programme that will aim to better use available ground time, and feature a 20% padding of the schedule to conduct certification by to handle any unexpected occurrences to still meet the February 2010 delivery target.
Source: Flight International