Sectional Aeronautical Charts are the primary navigational reference tool when flying VFR. In addition to airports and airspace, they also depict important navigational information such as lines of latitude and longitude, VOR stations, topography, and distinctive landmarks such cities, towns, roads, railroads, and bridges. 

Latitude is the angular distance north or south from the equator up to a maximum of 90 degrees. Longitude is the angular distance east or west from the Prime Meridian (located at Greenwich, England) up to a maximum of 180 degrees. Lines of latitude and longitude form a grid over the surface of the earth, allowing the exact location of any geographical point to be determined. For example, the city of Los Angeles is located at 34º N Latitude (thirty-four degrees north of the equator), and 118º W Longitude (one hundred eighteen degrees west of the Prime Meridian). Further precision can be obtained by specifying the number of minutes. One minute, represented on charts with the symbol ( ' ) is 1/60 of one degree. Los Angeles is 34º 03' N, 118º 14' W.

On a Sectional Aeronautical Chart the latitude/longitude grid is labeled along the edges in 30-minute intervals and forms square quadrants over the face of the chart. Tic marks along these lines allow the pilot to determine the exact position of any particular feature in terms of degrees and minutes of latitude and longitude. The distance represented by the grid tics along a line of longitude doesn't change, but the distance represented by the grid tics along the lines of latitude decreases when moving north since the lines within each quadrant become progressively shorter. 1/360th is one degree. 1 degree at the Equator is about 60 NM (1 degree is thus 60 minutes, or 60'). A Nautical Mile is 15% bigger than a statute mile; therefore, 1 NM is equal to 6000 ft at the Equator.