In an earlier paper it was suggested that developments in air navigation had created a requirement for a new form of air plotting chart. The chart illustrating the present paper was produced experimentally by one of the airlines to fulfil this requirement. The main factors taken into account in designing the chart were as follows:

(i) The air navigator is always working against time. He therefore requires his plotting chart to show as much navigational information as possible, so that he need not spend time looking things up in books or transferring information from other charts.

(ii) The scale must be limited by the requirement for easy handling in the cockpit, especially when the chart is intended for use in aircraft that have no navigation table.

(iii) The design of a chart that has to show as much information as possible on a small scale is chiefly a problem of avoiding congestion. The items that might be shown therefore require careful consideration and only those that make a justifiable contribution to the chart's navigational purpose should be included.

(iv) When flying under visual flight rules (VFR) the navigator's problems are less acute than under instrument flight rules (IFR). The chart should therefore be designed for IFR; it will always be adequate for the easier case of VFR.