To upload a PDF document and associate it to a specific airfield, you must add the ICAO code of the airport where you want the PDF to appear at the beginning of the pdf name ( Example: LSGG _Geneva_approach.pdf ). You can then upload the document in the «Appcharts» section. If Air Navigation cannot find an airfield matching the 4 letter prefix of the file, an error message will appear and the PDF will not be installed.