A new, fuel efficient airliner designed by the American plane maker Boeing, has made its maiden flight two years later than planned. Boeing has invested ten billion dollars in the project which has been bedeviled by delays and cost overruns. <br/><br/>It is the first commercial plane to be made largely from light weight carbon composite material that should use 20 per cent less fuel which means lower running costs. Airlines have ordered for more eight hundred of these planes.<br/><br/>