2.5 Operating Limitations: Speed, Visibility, Cloud Clearance and Height
In this lesson, I want to highlight four different Part 107 rules when it comes to the operating limitations of your Small Unmanned Aircraft System. We’ll talk about how fast you can go, the minimum visibility you need, and the finer points of cloud clearance, and then we’ll get into how high you’re allowed to fly.
Speed, Minimum Visibility, and Cloud Clearance
- Speed — Your sUAS may not be flown faster than a groundspeed of 87 knots, which is equivalent to 100 miles per hour; this speed limitation applies to any and all locations.
- Minimum Visibility — The minimum flight visibility, as observed from where you’re operating the drone from / where your remote controller is, may not be less than 3 statute miles (SM); and
- Cloud Clearance — If there are clouds, the UA must be at least 500 ft below the clouds and at least 2,000 ft horizontally from the clouds.
And just a quick note on that last point, because we get this question from students quite a bit. The cloud clearance language is a bit confusing.
What the FAA is saying is that if you’re flying directly below clouds or a cloud base, you need to make sure that you’re at least 500 ft below the clouds, vertically below the clouds. You can fly directly below clouds, you just need to maintain that distance. If you see clouds, but they are not directly above your drone, then you do not need to maintain the 500 ft part of the rule.
But what about 2,000 ft?
If you’re flying at the same altitude as clouds, like if you are in a mountainous environment, then you need to distance yourself horizontally from those clouds at least 2,000 ft. The 2,000 ft part of this rule only applies horizontally, meaning if you’re operating at the same altitude as the clouds.
Maximum Altitude Limit
OK, one more rule for you. Under Part 107, a Remote Pilot-in-Command cannot fly an unmanned aircraft higher than 400 ft above ground level (AGL), unless it’s flown within a 400-foot radius of a structure and does not fly higher than 400 ft above the structure’s immediate uppermost limit.
So, for example, if there’s a 1,200 ft telecommunications tower, you can inspect it with your drone, as long as you fly within 400 ft of the tower, horizontally or vertically, at all times.
And we talk more about airspace classes in a different module, but if flying your drone above a structure means you would be entering controlled airspace, then you would also be required to obtain airspace authorization prior to that flight.
I’ll see you in the next lesson!
