R.A.F. Bigsworth Chart Board, Type 'B', MK.2. Stores reference 6B/137. Wooden plotting board approximately 43.5 x 43.5cm fitted with a hinged articulated brass plotting arm and adjustable perspex rules. Clearly marked to reverse with Air Ministry King's crown stamps and February 1940 date code. The board has marks and wear but is in good '+' overall condition. The upper face has a sheet of paper pinned to it which has clearly been there for decades. The plotting arm is also in very good useable/working condition. The board retains the often missing canvas pen pocket and elasticated hanging loop. It comes with the original box of issue. This is also 1940 dated with matching serial number to the board. These chartboards were used by aircrew navigators and used to plot routes during flight. A lovely display item. Stock code M25157.