How to Read a VFR Sectional Chart

WHAT IS A VFR SECTIONAL CHART?

VFR sectional aeronautical charts are the primary navigational reference for visual flight rules pilots in the United States. Published by the FAA every 56 days (28 days for terminal area charts), these charts depict topographic features, airspace classifications, navigation aids, airports, and other information essential for safe visual navigation. The chart scale is 1:500,000, meaning one inch on the chart represents approximately 6.86 nautical miles.

AIRPORT SYMBOLS

Airports are among the most critical features on a sectional chart. Their depiction varies based on services available and runway configuration.

TOWERED VS. NON-TOWERED AIRPORTS

• Blue airport symbol: Indicates a towered (controlled) airport with an operating control tower • Magenta airport symbol: Indicates a non-towered airport • Runway pattern: Airports with hard-surfaced runways 1,500 feet or longer show the actual runway layout. Smaller airports appear as a circle with radiating marks

AIRPORT DATA BLOCK

Adjacent to each airport symbol is a data block containing essential information: • Airport name and identifier (e.g., "Van Nuys VNY") • CTAF or tower frequency • ATIS frequency (preceded by "ATIS") • Field elevation in feet MSL • Runway length of the longest runway (in hundreds of feet, with "70" meaning 7,000 feet) • Lighting codes (L = runway lighting available; asterisk indicates part-time or on-request lighting activated by pilot-controlled lighting)

AIRSPACE DEPICTIONS

CLASS B AIRSPACE

Class B airspace surrounds the busiest airports (such as LAX, JFK, and ORD). It is depicted with solid blue lines forming concentric shelves. Each shelf is labeled with the ceiling and floor altitudes separated by a horizontal line (e.g., "100/25" means ceiling 10,000 feet MSL, floor 2,500 feet MSL). An ATC clearance is required to enter Class B airspace.

CLASS C AIRSPACE

Class C airspace surrounds airports with radar approach control and a control tower. It is depicted with solid magenta lines, typically showing an inner ring (5 NM radius, surface to 4,000 feet AGL) and an outer ring (10 NM radius, 1,200 to 4,000 feet AGL). Two-way radio contact with ATC is required before entering.

CLASS D AIRSPACE

Class D airspace surrounds towered airports without radar approach control. It is depicted with a dashed blue line, typically extending from the surface to 2,500 feet AGL within a 4 NM radius. Two-way radio communication with the tower must be established before entry.

CLASS E AIRSPACE

Class E (controlled) airspace is depicted in several ways: • Magenta shading (fading outward): Class E begins at 700 feet AGL • Blue shading (fading outward): Class E begins at 1,200 feet AGL • Dashed magenta line: Class E surface area (typically around non-towered airports with instrument approaches)

CLASS G AIRSPACE

Class G (uncontrolled) airspace is not explicitly depicted. It exists from the surface up to the floor of the overlying controlled airspace. In most areas, Class G extends from the surface to 700 or 1,200 feet AGL, where Class E begins.

RESTRICTED AND PROHIBITED AREAS

Special use airspace is marked with blue hatching. Restricted areas (R-xxxx) have defined boundaries and altitudes, along with times of use and controlling agency. Prohibited areas (P-xxxx) are permanently off-limits (such as P-56 over the White House). Military Operations Areas (MOAs) are outlined with magenta hatching.

TERRAIN AND OBSTRUCTION DEPICTION

TOPOGRAPHIC FEATURES

Sectional charts use contour lines and color tinting to represent terrain elevation. Colors range from green (low elevation) through yellow and brown to white (high elevation, above approximately 8,000 feet MSL). Contour lines are spaced at 500-foot intervals on sectional charts.

MAXIMUM ELEVATION FIGURES (MEF)

Each quadrangle on the chart contains a bold blue number representing the Maximum Elevation Figure. The MEF indicates the highest known elevation within that quadrangle, including terrain and obstructions, rounded up to the next hundred feet with an additional 100-foot safety margin. The large number represents thousands and the smaller number represents hundreds (e.g., "4 5 " means 4,500 feet MSL).

OBSTRUCTIONS

Towers, antennas, and other obstructions are shown with standard symbols. The numbers adjacent to the symbol show the height above MSL (in bold) and above ground level (in parentheses). Obstructions above 1,000 feet AGL receive a group obstruction symbol or are highlighted. Lighted obstructions have a lightning bolt symbol; unlighted obstructions do not.

NAVIGATION AIDS (NAVAIDS)

• VOR: Depicted as a compass rose (a circle with radials) centered on the station location. The frequency, identifier, and Morse code are printed nearby. • VORTAC: A VOR co-located with TACAN (military distance measuring equipment), shown with a specific symbol combining the VOR compass rose with three dots • NDB: Non-Directional Beacon, shown as a small circle with dots around it

VICTOR AIRWAYS

Victor airways (V-routes) are federal airways based on VOR navigation aids. They appear as blue lines connecting VORs, labeled with the airway designator (e.g., V-23). The airway extends 4 NM on each side of the centerline and exists from 1,200 feet AGL to 18,000 feet MSL (the base of Class A airspace).

CHART READING TIPS

• Always check the chart edition date printed in the margin. Expired charts may contain outdated airspace or frequency information. • Use the chart legend on the front panel to decode any unfamiliar symbols. The legend is comprehensive and covers all standard depictions. • Cross-reference sectional chart information with the Chart Supplement (formerly Airport/Facility Directory) for detailed airport data not shown on the chart. • Practice identifying landmarks and correlating them with chart features before using the chart for actual navigation. • Digital versions of sectional charts are available through apps such as ForeFlight, Garmin Pilot, and FlyQ, which overlay GPS position on the chart in real time.