I can still remeber the sight that was fitted to the coaming in front of the co-pilot which consisted of a perspex sheet covered with graduated lines which the Co was supposed to use for ranging information. Not very effective in terms of accuracy I feel
This sounds very much like the CVBS. This grand-sounding piece of equipment was the Co-pilot's visual bombsight on the Vulcan. On the Vulcan it was actually calibrated using a form of collimation tube that was fitted into the nose some how. I watched one being done (in amazement). A vertical line could be used for tracking and horizontal lines for range.
The proper range line would vary with pitch which was proportional to speed and also depended on the 'standard' co-pilot adopting a standard seating position. Oddly it used to produce quite good results
