The 1st image shows the 'under drop' cut into the flow of the banked curve. The whole section uses segmented tapers, rising & falling, then tapering down to the lower tail section. You can see the concept of the construction in the 2nd image. 3rd image shows the 'gap set' spacers. In the last images you can see the bulk carving being carried out with the use once more of the 'arbotech'. The final image is taken from low down at the end of the tail & gives an odd distorted view of the curvature. At this stage the mid point board is still un - carved & so stands out 'on edge'.