Lateness isn't the only significant production problemfacing Boeing's Dreamliner787.

The composite-bodied aircraft is overweight â€“ as much as 8percent according to analysts at Bernstein Research. That's significant becausethe much-ballyhooed aircraft won't meet range specifications promised tobuyers, creating the potential that customer may demand discounts.

The data still listed at the 787 Web siteclaims a range of 7,650 to 8,200 nautical miles. However, based on the Bernsteinestimate, the range would drop to around 6,900 miles as the aircraft iscurrently designed and manufactured.

The difference would be critical for long haul air carriers,such as those that fly regularly between Asia and the United States. Forexample, the total distance from Chicago to Singapore is 8,144nautical miles.

Boeing spokesperson Loretta M. Gunter confirmed to DesignNews there is a problem with the aircraft's weight. "Boeing is notproviding a specific number concerning the weight of the first airplanes. ... We areworking with our partners on a number of ways to reduce weight."

She would not specify what those specific steps might be.Changes, once determined, will be introduced into the production schedule atintervals that will not result in future delays, she said.

Boeing rolled out the first 787 in a non-flying ceremony onJuly 8, 2007. At that time, the Dreamliner was the fastest selling wide-bodyairliner in history with nearly 600 orders.

A total of 861 Dreamliners have now been ordered by 56customers. So far this year, Boeing has reported 65 new orders and 65 canceledorders for the Dreamliner.

The Dreamliner was originally scheduled to enter service inMay 2008 and it is currently scheduled to enter into service in February 2010.The new design changes to reduce weight, however, are a wild card.

Boeing recently completedthe first engine runs on the 787, and is shooting for first flight soon.