With the availability of cheaper and better quality drones, hobby flying is booming not only in the US but around the world. While we might enjoy the thrill of flying, it’s a nightmare for air traffic controllers and pilots flying manned aircraft. What happens if you fly a drone above 400 feet or more, and it collides with a commercial plane? The risk to manned aircraft makes it absolutely necessary for us to know what is the maximum allowed height for commercial drones.
- Rule 107 (14 CFR Part 107)
- Exception for the 400 feet altitude limit
- What happens if you fly a drone over 400 ft?
- Controlled vs. Uncontrolled airspace
- From where the 400 feet altitude measured?
- How high can a drone fly?
- Altitude waiver for professional drone pilots
- Drone altitude limits in other countries
- Penalty for flying drone over 400 feet
- What is the maximum allowed height for commercial drones – Conslusion
We often hear reports of drones colliding with commercial aircraft in the media. A study by Bard College Center for the Study of the Drone reported 327 closed encounters between an unmanned drone and a commercial aircraft between December 2013 and September 2015.
In one incident (see video below), a drone flew very near to a helicopter, which could have resulted in an unfortunate incident.
Incidents like these prompted the FAA to enact new stricter rules and enforce the existing ones. One of these rules is the famous “400 feet altitude limit” rule, which we will discuss and understand here.
Rule 107 (14 CFR Part 107)
If you have owned and operated a drone or any other unmanned aircraft inside the USA, you might have heard of FAA Rule 107, which specifically discusses how pilots should operate Unmanned Aircraft System (UAS). This rule makes sure it does not endanger the US airspace for other manned flights. Legal language can often be hard to understand for common people like you and me, so let’s first see what the rule says and how we can interpret it to make sure we comply at all times.
Rule 107 gives numerous guidelines about the safe operation of a drone, but sub-part 51(b) of the regulation specifically goes over the altitude limitation of the drone. It states that;
The altitude of the small unmanned aircraft cannot be higher than 400 feet above ground level, unless the small unmanned aircraft:
(1) Is flown within a 400-foot radius of a structure; and
(2) Does not fly higher than 400 feet above the structure’s immediate uppermost limit.
Exception for the 400 feet altitude limit
The rule prohibits the drone operator from flying a drone above 400 feet measured from the ground level. There is an exception to the rule too. You can go above 400 feet of the ground level if you are within 400 feet of a tall structure like a building or a phone tower, etc. In that case, your maximum allowed altitude will be 400 feet above the structure’s top.
What happens if you fly a drone over 400 ft?
You must be thinking, why is the limit 400 feet and not some other random altitude? What happens if you fly a drone above 400 feet?
The answer is simple.
All manned aircraft are bound to stay above 500 feet from the ground except in controlled airspace near airports. The FAA left a 100 feet buffer zone to eliminate any “near miss” incidents and fixed 400 feet altitude as the red line above which you cannot fly your drone.
Statistics also show that most drone incidents took place above 500 feet. So the 400 feet limit along with a 100 feet buffer zone makes the flying safer for both the manned aircraft and the drones.
Controlled vs. Uncontrolled airspace
It is essential to understand that the limits imposed by Rule 107 are only applicable in uncontrolled airspace. So what is controlled & uncontrolled airspace?
Controlled airspace is the area within 5 miles of the immediate vicinity of an airport. Any flying activity by unauthorized civilian personnel is restricted within this area. I have used the word “restricted” here because it is not entirely banned. You can still fly your drone in the area after you get your LAANC authorization from the FAA.
LAANC (Low Altitude Authorisation & Notification Capability) is an automated permitting process that users can apply for from their phone App and get authorization in real-time. The process is entirely automated, and before approval is granted, multiple data points are checked to make sure the area is safe for unmanned flight operation.
Once the authorization is received via the App, you don’t even need to inform the air traffic controller unless explicitly requested to do so. Just follow the flight plan you submitted and enjoy.
One important thing to note here is that the exceptions for the 400 feet rule in the vicinity of tall structures no longer apply in a controlled area. Even if you are near a tall structure, you still have to keep your drone below the 400 feet limits measured from above the ground level. The LAANC authorization will state the following;
Altitude limits are absolute values above ground level which shall not be added to the height of any structures.
Uncontrolled airspace is any area outside of the 5-mile controlled area around the airports. When you are flying in an uncontrolled area, you will have to abide by Rule 107 limits on altitude, speed, line of sight, and other aspects of safe drone operation.
From where the 400 feet altitude measured?
This is one of the most misunderstood aspects of Rule 107. From where should you measure the 400 feet altitude limit? From the official statement, it might seem pretty clear that the reference point is the ground level.
The altitude of the small unmanned aircraft cannot be higher than 400 feet above ground level.
But there are some circumstances where this can get tricky. For example, you are standing on a hilltop that is located 90 feet above the normal ground level. Should your allowed altitude now be adjusted to 310 feet (since your take-off point is already 90 feet above the ground), or are you still allowed to go 400 feet above your take-off point? I searched the FAA rules & guidelines, crawled different communities but couldn’t get a clear explanation for this.
But here is my understanding.
Your reference point for the 400 feet should be the take-off point since aircraft always adjust their altitude in the presence of an obstacle like a hilltop. Since planes are not allowed to fly below 500 feet measured from the nearest surface (ground or any other structure), the airspace above you is safe up to 400 feet from where you take off.
But remember the rule of exception in 107 about remaining within 400 feet of the structure. If you are on a hilltop and going 400 feet above the hilltop (your take-off point), remember you have to remain within 400 feet from ALL direction so you can’t maintain the 400 feet altitude from the hilltop and wander off in one direction making the airspace safe. The aircraft might adjust their height only near the hilltop, but they might still fly at lower altitudes away from the hill, making the chances of collision real.
Rule of thumb: Fly below 400 feet of the ground level, always use your best judgment in case of ambiguity. Don’t take a risk that can endanger other humans.
How high can a drone fly?
If you are somewhat new to the world of drones or have never flown one before, you must be wondering how high can a drone fly? It depends on the manufacturer and specific model of the drone, but most drones can fly up to 10,000 feet altitude. Above that, the air pressure reduces sufficiently for the propellers to create enough thrust to gain further altitude.
Most notable drone manufacturers like DJI have programmed their drones to always remain below the 400 feet limit from the point of take-off. This provides an additional security feature in case you cross the red line unknowingly. But, remember that this is not totally foolproof. The software measure the altitude from the take-off point, so if you are standing on a structure or your favorite hilltop, that will be point zero for the drone, and it can still cross the max allowed limit.
Most modern drones also have other safety limitations programmed into them. One of my favorites is the DJI 2015 firmware update, which prevents its drones from flying over the Washington DC metropolitan area. This came after a rookie pilot crashed its Phantom 2 in the Whitehouse premises damaging some tree branches and probably scaring off some Secret Service agents.
Altitude waiver for professional drone pilots
Since drones are not only used by hobbyists for fun flying and aerial photography, they have found applications in many professional fields. One of them is the inspection of tall structures. FAA has commercial drone license programs as well as special activity waiver for commercial pilots.
For example, if there is a skyscraper being built, a drone can inspect the work at high altitude with ease instead of sending workers up there for in-person inspection (less costly and much safer).
Now, in uncontrolled areas, areas that are 5 miles outside of the airport, Rule 107 allows you to go an additional 400 feet above the tallest surface of the structure without any permit. But if the skyscraper is being built inside a controlled area, you will have to apply for a special permit (this is different than LAANC we discussed above). The FAA has stringent rules for issuing this special permit, and the entire process can take up to 3 months in some cases. You are required to notify the air traffic controller two days before the planned activity.
You can apply for this special activity permit on the FAA DroneZone site.
If you are a hobbyist flyer like me, you are currently stuck with the 400 feet altitude limit inside the controlled area (after your LAANC authorization) and 400 feet general limit outside a controlled area (plus the tall structure exceptions). Hobbyists cannot apply for the special activity waiver permit, which is only available for professional drone pilots.
Drone altitude limits in other countries
As we discussed that the 400 feet limit originates from how low can manned aircraft fly, we can expect the maximum allowed limits to be at or below 400 feet since aviation safety rules are almost the same internationally. Some countries might further reduce the maximum allowed limit to be on the safer side.
If you are unsure about your local regulations, visit your local air traffic regulatory authority (the equivalent of FAA in the US), and you will find the maximum allowed limit. Make sure you are always in compliance with your local drone laws.
Penalty for flying drone over 400 feet
FAA started registering all drones above 0.55 pounds back in 2015. As of December 2019, FAA has registered more than 1.5 million drones. Accordingly to a 2018 FAA updated guidelines, every drone owner must mark the outside of the drone with the registration number and keep proof of registration with him/her at the time of flying.
But what happens if you take your drone above 400 feet? The short answer is: probably nothing. FAA does not actively monitor uncontrolled airspace for drone law violations, and the responsibility to follow safe flying guidelines are up to us. As hobbyist drone flyers, we should keep our flying machines below the red line so that we don’t cause an accident that can endanger human lives.
If you are involved in an incident with a manned aircraft while flying above the red line, you might get heavily fined or even jail time depending upon the nature of the violation.
What is the maximum allowed height for commercial drones – Conslusion
Let’s recap all the things that we discussed here with the purpose of easy recalling;
- If you are within 5 miles of an airport, you can not fly without a LAANC authorization. Even if you have an authorization, you cannot go above 400 feet above ground level. NO EXCEPTIONS.
- If you are outside of the 5-mile radius of an airport, you can fly up to 400 feet above ground level. If you are within 400 feet of a tall structure, you can go 400 feet above the highest point of the structure.
- Most modern drones come with pre-programmed altitude limits but use that with caution. Make sure the reference point is correctly configured before take off.
Now that you are done with reading the latest FAA regulations, here is a quick video guide from Ken that goes over the rules once more if you are still scratching your head.
Related read: How to disable a drone on your property?
Disclaimer: Information provided in this article is only for educational purposes and should not be taken as legal advice in any capacity. Please visit the official website of your local air traffic control authority to verify and keep up to date with the latest information.