Boeing says the revised delivery date follows an assessment of the availability of an engine (the Rolls Royce Trent 1000) needed for the final phases of flight test this autumn.

Boeing said last month that the cumulative impact of a series of issues, including supplier workmanship issues related to the horizontal stabiliser and instrumentation delays, could push first delivery of the 787 Dreamliner a few weeks into 2011. The delay in engine availability has extended that estimate to mid-first quarter 2011.

Boeing says that the 787 Dreamliner schedule revision will not affect its financial guidance.

• This is the latest in a number of delays for the 787 Dreamliner project. Aircraft delivery is now running over 2 years late. Analysts believe Boeing is at risk of paying penalties to customers frustrated by these delays.