After a number of previous delays, the first 787 delivery had been scheduled for the first quarter of 2011.

Boeing says the new delivery date reflects the impact of an in-flight incident during testing last November and includes the time required to produce, install and test updated software and new electrical power distribution panels in the flight test and production airplanes.

"This revised timeline for first delivery accommodates the work we believe remains to be done to complete testing and certification of the 787," says Scott Fancher, vice president and general manager of the 787 programme. "We've also restored some margin in the schedule to allow for any additional time that may be needed to complete certification activities."

The 787 programme has been gradually returning individual airplanes to the flight test program. After receiving interim software and hardware improvements, four flight test aircraft have been subjected to extensive ground testing and a thorough review to ensure their readiness to return to flight. The remaining two aircraft will be returning to flight in the days ahead to bring the full flight test fleet back up to flight status.

Boeing does not expect the revised delivery date to have a material impact on its 2010 financial results.