|Title||USN Chart Plotting Board|
U. S. Navy - BU AER
Chart Lpotting Board
Mfr's Part No. FNA-65
Felsenthal & Sons, Chicago Mfg around 1972
The chart plotting computer consists of a square metal case with a plastic face and a mounted board made from thick card. It features a round plastic disk which can be rotated 360 degrees and a top central arrow indicating north. In the bottom corner of the chart, "CHART PLOTTING BOARD / MARK 6A" is printed, while the opposite corner has a button for unlocking the case. The chart has a small pull-out calculator at the bottom of the board, with "Computer Mark 8-B" inscribed on the centre. It consists of a circular slide, set for correcting altitude computations, with temperature and air pressure scales, as well as a table on the right for marking out the results.
Inside the chart case are three transparent plastic sleeves, which open at the sides and feature a section at the top with small rod for attaching to the chart plotter.
The handmade ruler found in the plotting chart is a cardboard square with a small hole punched in the bottom left corner. A scale is marked in blue pen along the top, marking 0:55 in approximate equal measurements