If you’re studying to pass the FAA Part 107 exam, one of the most important skills you need to learn is how to read a sectional map. Sectional charts are used by pilots to navigate and plan flights, and understanding how to read latitude and longitude on these maps is a key part of that process. While this might seem intimidating to beginners, don't worry! In this guide, we’ll break down the basics of reading latitude and longitude on a sectional map in a simple and easy-to-understand way.

What is a Sectional Map?

Before we dive into reading coordinates, let’s quickly cover what a sectional chart is. A sectional chart is a detailed map used by pilots to navigate and plan flights. These maps show a variety of important information, such as:

• Airspace boundaries

• Navigation aids (like radio beacons)

• Obstacles (like towers and mountains)

• Airports and runways

They are crucial for flight planning because they provide the layout of the airspace in a given region, and understanding how to read latitude and longitude on these maps is vital for identifying specific locations and planning safe flights.

What are Latitude and Longitude?

Latitude and longitude are a system of geographic coordinates used to pinpoint locations on the Earth’s surface. They are measured in degrees:

• Latitude: Measures the distance north or south of the Equator. The Equator is at 0° latitude, and the poles are at 90° north and south.

• Longitude: Measures the distance east or west of the Prime Meridian, which is located at 0° longitude. Longitude lines extend all the way around the Earth, from the North Pole to the South Pole.

  
  

When reading coordinates, you’ll encounter them as a combination of latitude and longitude. For example, 39° 57.0' N, 75° 11.0' W refers to a location in the Northern Hemisphere, east of the Prime Meridian.

Step-by-Step: How to Read Latitude and Longitude on a Sectional Chart

Look at the Grid System

Sectional charts are overlaid with a grid of latitude and longitude lines that create boxes, like a giant tic-tac-toe board. These grid lines help you identify specific locations on the map.

• Latitude lines run horizontally (left to right). Each horizontal line represents a specific degree of latitude.

• Longitude lines run vertically (up and down). Each vertical line represents a specific degree of longitude.

These lines create a coordinate system that allows you to pinpoint any location on the map.

Understand the Coordinate Notation

In aviation sectional charts, the coordinates are typically shown in degrees, minutes, and sometimes seconds. Let’s break this down:

• Degrees (°): The main unit of measurement in latitude and longitude. For example, "39°" represents 39 degrees.

• Minutes ('): There are 60 minutes in a degree. For example, "39° 57.0'" means 39 degrees and 57 minutes.

• Seconds ("): This is sometimes included for even more precision but isn’t commonly seen on sectional charts.

For example, a point on a sectional chart might be marked as 39° 57.0' N, 75° 11.0' W.

Reading Latitude

Latitude coordinates are given in degrees north (N) or south (S) of the Equator. On sectional charts, you'll see lines marked with numbers, like "30", "31", "32", etc., which represent whole degrees of latitude. Between these numbers are smaller lines that represent the minutes of latitude.

• Example: If you see "39°" and then another line in between "39°" and "40°," that represents one minute (1/60th) of latitude. If the line is halfway between the two, that’s 39° 30.0' N (30 minutes north of 39°).

  
  

Reading Longitude

Longitude coordinates are given in degrees east (E) or west (W) of the Prime Meridian. Longitude lines are also marked on the sectional chart, usually with numbers like "75," "76," "77," etc., which represent whole degrees of longitude.

• Example: If a location is shown as "75° W," that means the location is 75 degrees west of the Prime Meridian.

  
  

Using a Grid to Find Specific Locations

Once you understand how the grid system works, you can use the grid lines to find specific locations.

• Identify the nearest latitude and longitude lines: Look at the nearest horizontal (latitude) and vertical (longitude) lines to the point you're interested in.

• Estimate the position: Find the smaller divisions between these lines. If you need to be more precise, note how far along the grid the location is in terms of minutes.

  
  

Example

Let’s go through an example to make sure you understand how to use latitude and longitude to pinpoint a location:

• Suppose you’re looking at a sectional chart and see the coordinates 39° 57.0' N, 75° 11.0' W.

  • The 39° 57.0' N tells you the location is 39 degrees and 57 minutes north of the Equator.

  • The 75° 11.0' W tells you the location is 75 degrees and 11 minutes west of the Prime Meridian.

By locating the intersection of these two lines on the map, you can identify the exact point where these coordinates meet.

Tips for Beginners

• Practice: It may take some time to get used to reading these maps, so the more you practice, the easier it will become. Try looking at a sectional chart and identifying locations using the grid system.

• Use a ruler: A simple ruler can help you draw straight lines between the latitude and longitude lines to pinpoint locations more accurately.

• Ask for help: Don’t hesitate to ask an experienced pilot or instructor to show you how to read the chart or clarify any confusing points.

  
  

Why is This Important for the FAA Part 107 Exam?

The FAA Part 107 exam is required to become a certified drone pilot. Sectional charts are an essential tool for flight planning and airspace awareness, which are key components of the exam. Understanding latitude and longitude will help you:

• Navigate in controlled airspace: By reading sectional charts, you can avoid flying into restricted airspaces.

• Plan your drone operations safely: Knowing how to identify specific locations helps you ensure you’re in safe areas for flying.

• Read coordinates for weather stations or navigational aids: Understanding coordinates will help you find weather stations or radio beacons, which are useful for flight planning.

  
  

Conclusion

Learning how to read latitude and longitude on a sectional map is an essential skill for passing the FAA Part 107 exam. While it may seem complicated at first, with a bit of practice, you'll get the hang of it. Start by understanding the grid system, then practice reading coordinates until it becomes second nature. This skill will not only help you pass the exam but also ensure you can plan your drone flights safely and confidently.

Good luck with your studies and happy flying!

 About the author

Michael Hill is the Founder / CEO of Uncrewed Aerospace, an award-winning Drone Technology Company, that helps clients integrate Uncrewed Technology & Ai on the land, in the air, and at sea. Follow our work at www.uncrewedaerospace.com #TheDronePro