Aeronautical Charts

Whenever you fly away from your home base airport, you will need aeronautical charts to help you navigate accurately. The chats you will be using provide a detailed portrayal of the topography of the covered area and also include aeronautical information. Because you will navigate initial with visual reference to objects or landmarks on the surface, topography information will be very useful. The National Ocean Service (NOS) publishes several charts which supply an abundance of information for pilots operating under visual flight rules. You can find these charts at http://myairplane.com∞ .

Sectional Charts

The charts most commonly used for VFR flight are sectional charts. They cover all of the 48 mainland states, plus Alaska, Hawaii Puerto Rico, and the Virgin Islands. To allow for greater detail, each chart shows a section of the country and is given the name of a primary city within its coverage.

Topographical information includes relief features (such as terrain contours), cities, towns, rivers, highways, railroads and other distinct landmarks which you can sue as visual checkpoints. Along with airport depictions, sectional also contain aeronautical information pertaining to navigation and communication facilities, as well as airspace and obstruction. The scale of a sectional chart is 1:500,000. This means that each inch on the sectional is the equivalent to 500,000 actual inches. This translates to one inch on the sectional equaling approx. seven nautical or eight statue miles on the earth?s surface. Most sectionals are revised every six months, but some outside the 48 mainland states are on an annual revision schedule.

The chart index on the front plane of a sectional tells you the names of the adjoining charts. If your route of flight is near the edge of a chart, you should always take along appropriate adjoining charts. The back panel contains detailed legend information which will receive special coverage later in this section.

Aeronautical charts are folded for easy handling, storage and identification during flight. Most are printed on both sides in order to reduce the total number of charts required. When you look at the front panel of a sectional, you will notice arrows labeled ?North? and ?South.? When you unfold the charts, these arrows direct you to the northern and southern portions of the covered area.

Important terrain information is shown shown on the front of each chart. The colors, or gradient tins assigned to each thousand feet of elevation are shown by a graph. Colors range from green as sea level to brown for elevations above 12,000 feet MSL. The contour internals appearing on the sectional are also shown on the front. These contour lines connect areas of equal elevation, and are a good reference for determining the mean sea of level elevations of the terrain you?re flying over. The front panel also contains information concerning the highest terrain and other known features for the entire area of the chart, including maximum elevation figures (MEFs). MEFs are rounded to the next 100-foot level and adjusted upward approximately 100 to 300 feet, depending on the nature of the terrain and/or obstacles.

VFR Terminal Area Charts

Whenever you?re flying VR in or around Class B airspace, VFR terminal area charts will help significantly with orientation and navigation. These charts have a large scale (1:250,000) and give you a more detailed display of topographical features than sectional charts. VFR terminal charts are revised every six months.

Terminal area charts show the lateral limits of the various sections of the Class B area. The lateral boundaries are marked by a heavy blue line which encircles the Class B area. Ceilings and floors are designated in hundreds of feet MSL. On sectional charts, the availability of a terminal area chat is indicated by a wide, blue band which encloses the Class B airspace and reflects the boundaries of the terminal area chart.

The most efficient means of avoiding conflicts with major traffic in and out of a Class B area is to refer to the VFR flyways shown on the reverse side of some terminal area charts. VFR flyway planning charts depict multiple routes for use by VFR pilots as alternatives to flight within Class B airspace. They are not intended to discourage requests for VFR operations, but are designed to aid pilots planning to avoid heavily congested areas, such as IFR arrival and departure routes. Flyway charts omit most of the terrain features and geographic information found on terminal area charts because they are for planning, not navigating. However, major landmarks are shown as visual aids to orientation. Although these routes go through areas of reduced air traffic congestion, you should always be aware that flying through them does not mean that you have separation from other aircraft.

World Aeronautical Charts

A world aeronautical chart is similar to a sectional, but it uses a scale of 1:1,000,000. At this scale approximately 14 nautical miles, or 16 statue miles, are represented by one inch on the map. The symbols are basically the same as those found on sectionals, but some of the detail is omitted due to the smaller scale.

In addition to the contour intervals and elevation information, the front shows a map index of the charts which can be placed together to incorporate the total network. The date at which the chart becomes effective is shown, as well as the date it is expected to become obsolete for navigation. Usually, this date is keyed to the publication schedule of the next edition. Most WAC charts are revised on a yearly basis.