FAA Part 107 Guide: What is the Difference Between MSL and AGL?

part 107 license Nov 17, 2021

Becoming a drone pilot can sometimes feel like you’re trying to learn a whole new language. But don’t worry—we’re here to translate some of the lingo for you and help you take flight successfully (and legally). 

If you’re studying for Part 107 to get your drone license, it’s crucial to make sure you’ve got all the answers you’re looking for and are confident with your knowledge of the rules and regulations. Once you’ve got that under your belt, you can pass the test with flying colors and take to the skies. 

Let’s help you out a bit by going over one of the major topics covered in Part 107 of the Remote Pilot License exam: What is the Difference between MSL vs. AGL?

What is Mean Sea Level (MSL)?

Mean Sea Level (MSL) and Above Ground Level (AGL) are fancy terms for the measurements of altitude. An MSL value represents the distance between an object and sea level. A standardized sea level value is used across the board.

What is Above Ground Level (AGL)?

On the other side, AGL represents the distance between an object and the ground level.

When Should You Use MSL? 

MSL isn’t just a number—it is essential for maintaining altitude. By combining MSL with air pressure values to stay steady. MSL is also used in sectional charts or maps of the airspace. When you’re reading sectional charts, you’re reading MSL values. 

You should use MSL when you’re flying over rough areas with hills, bumps, and changing terrain because the AGL of the terrain will vary too much. 

When Should You Use AGL? 

Speaking of AGL, AGL is often used when you’re flying a drone closer to the ground.

While MSL is used to warn you of how high you can fly your drone for quality and function, AGL values are used to measure local laws and regulations. So, if you’re double-checking that you’re abiding by the 400-foot rule, make sure you’re looking at the AGL value, rather than the MSL value––otherwise, you’ll end up a bit confused (and a little low in altitude). 

What is the Difference Between MSL & AGL?

Need the Reader’s Digest version? No stress. Here are the key differentiators between MSL and AGL:

  • MSL = your true altitude above a standardized sea level.
  • AGL = your altitude above your current ground level. 
  • MSL is used in sectional charts, when flying over bumpy landscapes, and in calculating the flying capacities of drones.
  • AGL values are used when flying near the ground and in legal regulations and laws, like the 400-foot rule.
  • If you’re stressed and don’t know which is which, just remember: MSL values are higher than AGL values.

More Part 107 Test Prep

Ready to take to the skies? If you’re studying for the exam, you might be one of many who discovered that the Remote Pilot License (Drone License) test is a bit more complicated and stressful than they thought. 

To help, Altitude University provides simple, user-friendly education and courses for beginners looking to master their drone skills and knowledge. If you want to learn more about MSL and AGL, our Part 107 Test Prep Course is the perfect place to start. 

Feel confident and finally get your driver’s license for the sky––without the headache. Let’s walk you through it, unlock your pilot potential, and accelerate your journey to making money with drones. Get ready for takeoff and join our community of over 12,000 students today!

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