Sectional Aeronautical Charts are designed for visual navigation of slow to medium speed aircraft. Topographic information as well as visual checkpoints are depicted and used for flight under visual flight rules (VFR). Checkpoints include populated places, drainage patterns, roads, railroads, and other distinctive landmarks. The aeronautical information on Sectional Charts includes visual and radio aids to navigation, airports, controlled airspace, restricted area, obstructions, and related data. (Scale 1 inch = 6.86nm/1:500,000; 60 x 20 inches folded to 5 x 10 inches) Revised semi-annually, except most Alaskan charts are revised annually.