Final assembly of the first Airbus A350 will slip into April, missing the airframer's first-quarter target.

Airbus had delayed the A350's final assembly from the end of 2011 but intended to begin the process in the first three months of 2012.

Chief executive Tom Enders had said that the work would begin in March.

But EADS chief Louis Gallois, speaking during the company's annual results presentation in Paris today, said the final assembly of the A350 would start at the beginning of April.

This initial aircraft will be the static test airframe. Gallois said the first flight-test aircraft would be on the final assembly line "in the summer".

EADS had cautioned today that the A350's development remained challenging and that the schedule for final assembly was "tightening".

Source: Air Transport Intelligence news