Boeing has reportedly pushed back first flight of its 787 aircraft from the end of September into October.

The Seattle Post Intelligencer, citing people familiar with the matter, reports the manufacturer has pushed back the first flight mainly as a result of the complexity of installing and integrating various systems on the 787.

In particular it says it has taken longer than expected to get the critical flight control systems and software up and running, and communicating with the other systems.

Boeing rolled out the 787 last month. Boeing CEO Jim McNerney subsequently said that, while still aiming for a September first flight, the company had put contingency plans in place in case it slipped into October. He maintained that, even with a slip, delivery of the first aircraft to All Nippon Airways in May 2008 would remain possible.

The US manufacturer could not immediately be reached for comment, but the Seattle Post Intelligencer says Boeing would not confirm the first flight of the aircraft was scheduled for October.

“We remain on schedule for entry into service in 2008," Boeing said in a statement to the paper. "The pockets of behind-schedule condition vary. Since recovery plans are in place, our overall assessment is that we are on schedule."