Part 107 operating rules: altitude, speed, visibility and clouds
The core limits of 14 CFR 107.51 and related rules: 400 ft AGL, 87 knots, 3 statute miles, cloud clearance, visual line of sight and night lighting.
Checked against the rules in force on 2026-10-01Most Part 107 test questions about flying rules come from a handful of numbers in 14 CFR 107.51 and the sections around it. Learn the numbers, and learn the traps the test builds around them.
The four limits in 107.51
- Groundspeed: no more than 87 knots (100 mph). It is groundspeed, so a tailwind counts.
- Altitude: no higher than 400 feet AGL. The exception: within a 400-foot radius of a structure, you may fly up to 400 feet above the structure's top. A 300-foot tower lets you go to 700 feet AGL, but only while you stay within 400 feet of it.
- Visibility: at least 3 statute miles, measured from the control station.
- Cloud clearance: at least 500 feet below clouds and 2,000 feet horizontally from them.
The test likes to swap AGL for MSL, knots for miles per hour, and nautical miles for statute miles. Read every unit.
Seeing and avoiding
You, or a visual observer, must keep the drone in visual line of sight with unaided vision. Glasses and contact lenses are fine; binoculars and FPV goggles do not count. A visual observer must be able to communicate with you at all times.
Small unmanned aircraft yield right of way to every aircraft. You may not pass over, under or ahead of another aircraft unless well clear, and you may not fly so close that you create a collision hazard.
Night and twilight
Civil twilight is the 30 minutes before official sunrise and the 30 minutes after official sunset (outside Alaska). During twilight and at night the drone needs anti-collision lighting visible for 3 statute miles. You may dim it for safety, but never turn it off. Night flight also requires that your initial test or training was taken after April 6, 2021.
Other rules you will meet
- One person may not operate more than one drone at the same time.
- No hazardous materials on board.
- No flying from a moving aircraft. From a moving land or water vehicle only over a sparsely populated area, and never while carrying someone else's property for hire.
- No careless or reckless operation, and no dropping objects in a way that creates an undue hazard.
Many of these limits can be waived through FAADroneZone. A few, such as the alcohol rules and the hazardous materials ban, cannot.
Sources: 14 CFR 107.29 · 14 CFR 107.31 · 14 CFR 107.37 · 14 CFR 107.51
Try 5 questions on this topic
Free sample questions with a debrief for each answer.
Under 14 CFR Part 107, what is the maximum altitude for a small UA that is NOT within a 400-foot radius of a structure?
What is the minimum flight visibility for a Part 107 operation?
What minimum distance from clouds must a small UA maintain under Part 107?
Which may you use to keep your small UA within visual line of sight?
A helicopter approaches the area where your drone is flying. Who has the right of way?
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