Research of semiotic aspects Lithuanian military air navigation charts was based on the semantic, graphic and information load analysis. The aim of semantic analysis was to determine how the conventional cartographical symbols, used in air navigation charts, correspond with carto-linguistic and carto-semiotic requirements. The analysis of all the markings was performed complex and collected by questionnaire were interviewed various respondents: pilots, cartographers and other chart users.
The researches seek two aims: evaluate information and graphical load of military air navigation charts. Information load evaluated to calculate all objects and phenomenon, which was in 25 cm² of map. Charts analysis showed that in low flight charts (LFC) average information load are 4 - 5 times richer than in the operational maps. Map signs optimization on LFC has to be managed very carefully, choosing signs that can reduce the load of information and helps for the information transfer process. Graphical load of maps evaluated of aeronautical maps is not great (5 - 12%) and does not require reduction the information load and generalization of charts. Air navigation charts analysis pointed that not all air navigation sings correspond carto-semiotic requirements and must be improved. The authors suggested some new sings for military air navigation chart, which are simpler, equivalent to human psychophysical perception criteria, creates faster communication and less load on the chart.