In the previous part of this series, we covered the 5 basic types of controlled airspace classes: class A, B, C, D & E and how they look on a VFR chart. However, there is also a class G airspace. It is uncontrolled airspace, unlike the rest. Reading classes of airspace, airports, and tons of other symbols on a VFR (Visual Flight Rules) Sectional Chart can be a tedious task for a beginner. Thus, let’s break them down into fundamental terms:

What is a class G airspace?

Class G is specified as uncontrolled airspace. That means that there are no services provided to manned aircraft in this airspace. Everything excluding A, B, C, D or E falls under the class G airspace. This airspace can be generally found below class E airspace. However, class G is not represented on a sectional chart. Thus, to identify a class G airspace, one must first look for signs of any of the 5 controlled classes. If they’re absent, then it is the class G airspace. The good part about this class of airspace is that a pilot (manned or unmanned aircraft) does not require any special approval from the FAA to operate here.

Basic Terminologies in a VFR Chart

A sectional chart has lots of elements that will help a remote pilot read the map effectively. Understanding each element and terminology of the chart will give you the knowledge of what each symbol, color or number signifies. Some of the basic elements of a sectional chart are:


A legend is a table consisting of symbols, numbers, colors and what each one of them means. A legend of the particular area chart will help you identify the airports, classes, altitude, elevation, etc, of that area.

VFR Chart legend
An example of a legend

Maximum Elevation Figure (MEF) & Topography

The Maximum Elevation Figure (MEF) on a sectional chart tells pilots what is the lowest altitude they can safely fly up to without posing a risk of colliding with objects. This number is rounded off to the nearest 100-foot value and the last two digits are not shown on the map. Thus, if the MEF for a quadrant on a chart is 48,000ft, then on the chart it would appear as the number 48 written in a big blue font. In the case of MEF being 12,500ft, for instance, it would be written as 125. The MEF is of more importance to drone pilots than aircraft pilots as drone pilots fly their drones Beyond Visual Line of Sight (BVLOS) and have to mainly rely on the drone’s camera feedback and these sectional charts of that area.

VFR chart
In the map above the MEF would be 2,600ft.

The topography of an area can be identified by two things on a VFR chart. Firstly, by noticing the folds created on the represented terrain. Secondly, this terrain is color-coded based upon its elevation from the sea level. Terrain which is colored dark brown or yellow is highland and the greener and bluer shades signify land closer to the sea level.

topography color code
A sample topographical color-coding based on the maximum altitude of 19,633ft.

Airport Depiction

On a VFR chart, airports are depicted primarily in two ways- Airports with control towers and Airports without control towers. Airports with control towers are depicted with a blue circle and ones without are enclosed in a magenta circle. Airports with towers are generally in controlled airspace and the pilot would require approval to fly near that airport. Note: Airports are not always depicted in an enclosed circle. Airports with runways greater than 8069ft are depicted in a small cross or backslash shape.

airport depiction on sectional chart
VFR chart airports

Given above is an example of a Dallas airport. The basic symbols and numbers listed above can help us understand the details of the airport. This is an airport with a control tower as the symbol is blue in color. The Control Tower (CT) Frequency given is 123.7. The ATIS Frequency is the radio frequency which pilots can use to inquire about the weather report. Here it is 120.15. In airports without control towers (in magenta) could have an AWOS Frequency instead of an ATIS. The UNICOM Frequency is not of much importance to remote pilots as it is mainly used for non-flight services. The NO SVFR symbol means that this airport prohibits fixed-wing Special VFR operations. 487 is the airport elevation and L88 means that the airport has lighting along its 8800ft runway.

Additional Symbols

A very important piece of information for remote pilots is the obstruction symbols. For instance, Antenna Towers are crucial symbols that show the height of the obstacle. This is essential not only for flight safety but if a drone is inspecting a tower, for example, the pilot can tell the height of the tower by looking at the AGL and MSL value written beneath the tower’s symbol.

obstruction symbols

Other important symbols for drone pilots include stadiums, aerial cables, power lines, VFR Waypoints and Special Activity UA.

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