14 CFR 107.51

How high and how fast can you fly a drone?

Part 107 caps a small drone at 400 feet above the ground and 100 miles per hour. Here is the rule, its one altitude exception, the exam traps and practice questions, with the FAA source under each answer.

Part 107, explained · Last reviewed October 25, 2026 against the eCFR and faa.gov. UAV Campus is not affiliated with the FAA.

How high and how fast can you fly a drone under Part 107?

No higher than 400 feet above ground level, and no faster than 87 knots (100 miles per hour) groundspeed. The one altitude exception: within a 400-foot radius of a structure, you may fly up to 400 feet above the structure's immediate uppermost limit.

Source: 14 CFR 107.51(a)-(b)

What the regulation says

§ 107.51 Operating limitations for small unmanned aircraft.

A remote pilot in command and the person manipulating the flight controls of the small unmanned aircraft system must comply with all of the following operating limitations when operating a small unmanned aircraft system:

(a) The groundspeed of the small unmanned aircraft may not exceed 87 knots (100 miles per hour).

Read all of § 107.51

(b) 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.

(c) The minimum flight visibility, as observed from the location of the control station must be no less than 3 statute miles. For purposes of this section, flight visibility means the average slant distance from the control station at which prominent unlighted objects may be seen and identified by day and prominent lighted objects may be seen and identified by night.

(d) The minimum distance of the small unmanned aircraft from clouds must be no less than: (1) 500 feet below the cloud; and (2) 2,000 feet horizontally from the cloud.

Source: 14 CFR 107.51 (eCFR, current as of 2026-10-21)

Exam traps

  • The speed limit is groundspeed, not airspeed: 87 knots, which the rule also writes as 100 miles per hour.
  • The 400 feet is above ground level (AGL), not above mean sea level (MSL).
  • Near a structure the ceiling becomes 400 feet above the structure's immediate uppermost limit, but only while the drone stays within a 400-foot radius of it.
  • The same section also sets the weather minimums: 3 statute miles of visibility, 500 feet below and 2,000 feet horizontally from clouds.

Try it: practice questions

Similar to the FAA test, not the actual test questions.

Practice question 1

In accordance with 14 CFR Part 107, except when within a 400′ radius of a structure, at what maximum altitude can you operate sUAS?

  1. A 600 feet AGL.
  2. B 500 feet AGL.
  3. C 400 feet AGL.
Show the answer
Answer: C. 400 feet AGL.

(14 CFR Part 107.51 states that the max altitude is 400 above ground level (AGL))

FAA source: 14 CFR 107.51(b)

Practice question 2

The maximum speed a sUAS is allowed to fly under Part 107 is

  1. A 100 mph
  2. B 100 kts
  3. C 87 mph
Show the answer
Answer: A. 100 mph

FAA source: 14 CFR 107.51(a)

Practice question 3

What is the maximum altitude at which a sUAS can be flown at night?

  1. A 400 feet.
  2. B 300 feet.
  3. C 200 feet.
Show the answer
Answer: A. 400 feet.

FAA source: 14 CFR 107.51(b)

Can you fly higher than 400 feet next to a tower or building?

Yes, within a 400-foot radius of the structure you may fly up to 400 feet above its immediate uppermost limit. Farther than 400 feet from the structure, the 400-foot AGL limit applies again.

Source: 14 CFR 107.51(b)

Can the FAA waive the 400-foot or 100 mph limit?

Yes. 107.51 is on the list of Part 107 rules a certificate of waiver issued under 107.200 may authorize a deviation from.

Source: 14 CFR 107.205(i)

Take the free practice test Create your free account