A350-900 - MSN16 (VN #3) VN-A888 Feb 8, 2015 8:55:38 GMT 1 FabienA380, Baroque, and 2 more like this
Post by philidor on Feb 8, 2015 8:55:38 GMT 1
Flight tests provide a lot of information that is used by the manufacturer to improve the aircraft design, and which are included in certified specifications. From that point of view, it would be best to wait until the test programme has been completed before beginning building customer frames, but that is financially impossible because you need to begin churning out aircraft as soon as possible, and widebodies often have long lead times. As a consequence, the manufacturer has to settle for a compromise. Airbus has a number of frames (about 20 ? I don't know exactly) that have been built while the tests were in process, and that now need some rework to meet certification standards. This process, requiring additional working space (tents) is now holding A350 deliveries.
Just to compare, Boeing took more risks with the 787 programme, a large number of frames being built before certification and later needing extensive rework before delivery (not only because of deliberate changes, but also because of manufacturing issues resulting in so-called 'travelled work'). Though the first deliveries occurred in 2011, the extent of the required rework was such that some early-built frames still have not been upgraded to certification and are still waiting on the flightline.
Airbus' present rework issue is comparatively much smaller.