The FAA's Part 107 regulations, officially titled "Operation and Certification of Small Unmanned Aircraft Systems," form the legal foundation for commercial drone operations in the United States. Whether you are flying for aerial photography, precision agriculture, infrastructure inspection, or any other business purpose, Part 107 is the rulebook that governs how, where, and when you can legally operate. Understanding these operating limitations is not just about passing the Remote Pilot Certificate knowledge test — it is about conducting every flight safely and legally in a shared national airspace system that also contains manned aircraft, often flying far lower than many people assume.
This article walks through the key operating limitations defined in 14 CFR Part 107, explains the reasoning behind each rule, and highlights the specific numbers and concepts that appear most frequently on the FAA Aeronautical Knowledge Test for remote pilots.
Altitude Limitations
Under Part 107, small unmanned aircraft (sUAS) may not be operated higher than 400 feet above ground level (AGL) in uncontrolled airspace. This ceiling exists to keep drones well below the minimum safe altitudes at which manned aircraft typically operate, protecting both manned and unmanned traffic from midair collisions.
There is one important and commonly tested exception to the 400-foot rule: when operating within a 400-foot radius of a structure, the sUAS may fly up to 400 feet above the top of that structure. For example, if you are inspecting a 500-foot communications tower, you may legally operate your drone up to 900 feet AGL — 500 feet for the tower plus 400 feet above it. This exception is designed to support the legitimate commercial need to inspect tall structures while still keeping drones tethered (conceptually) to those structures rather than roaming freely at high altitudes.
Airspace Requirements
Part 107 permits operations in Class G (uncontrolled) airspace without any prior authorization. Operations in controlled airspace — Classes B, C, D, and the surface area of Class E — require either prior authorization from the FAA or a real-time authorization through the Low Altitude Authorization and Notification Capability (LAANC) system. LAANC is an automated tool that provides near-instantaneous approval for flights in many controlled airspace environments up to FAA-published altitude ceilings.
For areas not covered by LAANC, remote pilots must apply through the FAA's DroneZone portal. Operations near airports are a primary concern because the traffic density and approach/departure paths create collision risk. Knowing which class of airspace you are in — and checking appropriate charts and apps before every flight — is a fundamental pre-flight responsibility under Part 107.
Visibility and Cloud Clearance
Part 107 mandates that the remote pilot in command (RPIC) maintain a minimum flight visibility of 3 statute miles from the control station. This is a ground-level measurement from where the operator is standing, not from the aircraft itself. If the surrounding visibility drops below 3 miles due to haze, smoke, fog, or precipitation, operations must cease.
Cloud clearance requirements mirror the VFR minimums for Class G airspace below 10,000 feet MSL: the sUAS must remain at least 500 feet below clouds and at least 2,000 feet horizontally from clouds. These buffers exist because manned aircraft can emerge from cloud bases very rapidly, and a remote pilot has far less time to react than a pilot inside a cockpit scanning for traffic. Note that these minimums apply to the drone's actual position, not just the operator's approximate estimate — meaning careful altitude management is critical when clouds are nearby.
Daylight and Lighting Requirements
By default, Part 107 restricts operations to daylight hours and civil twilight. Civil twilight begins 30 minutes before official sunrise and ends 30 minutes after official sunset. During civil twilight, the drone must be equipped with anti-collision lighting that is visible for at least 3 statute miles. The lighting requirement ensures that even in reduced-light conditions the sUAS can be seen by manned aircraft.
Night operations — meaning operations outside of civil twilight — were previously available only by waiver but are now permitted under standard Part 107 rules, provided the sUAS is equipped with the same anti-collision lighting visible from 3 miles. Remote pilots must be aware that local official sunrise and sunset times vary by geographic location and date, so checking an authoritative source (such as the NOAA solar calculator or an official chart supplement) before each flight is essential.
Visual Line of Sight (VLOS)
One of the most operationally significant limitations in Part 107 is the requirement to maintain visual line of sight (VLOS) with the sUAS at all times. The RPIC (or a visual observer, if one is used) must be able to see the aircraft with unaided vision — meaning no binoculars, cameras, or first-person view (FPV) goggles as the sole means of tracking the aircraft. The pilot must be able to see the drone well enough to know its location, altitude, attitude, and direction of flight, and to scan the airspace for other traffic and hazards.
A visual observer (VO) may assist the RPIC by maintaining eyes on the aircraft while the RPIC focuses on controlling it, but the VO does not replace the RPIC's responsibility — the RPIC and VO must maintain effective communication with each other at all times, which may be accomplished using radios or other communication aids and does not need to be unaided. Operations beyond visual line of sight (BVLOS) are not permitted under standard Part 107 rules and require an FAA waiver or special authorization.
Speed and Weight Limits
The maximum allowable groundspeed for a Part 107 operation is 100 miles per hour (87 knots). The weight limitation defining a "small" UAS under Part 107 is a total takeoff weight of less than 55 pounds, including everything onboard (payload, batteries, attachments). Aircraft at or above 55 pounds fall outside the standard Part 107 framework and require different authorization.
Carriage of Hazardous Materials and Other Restrictions
Part 107 prohibits the carriage of hazardous materials capable of causing injury or damage to persons or property. Operating from a moving vehicle or aircraft is generally not permitted, except in sparsely populated areas. A single RPIC cannot operate more than one sUAS simultaneously. The remote pilot is also prohibited from operating in a careless or reckless manner that endangers the life or property of another — a broad safety catch-all that mirrors similar language in the manned aviation regulations.
Waiver System
Many of the operating limitations described above can be waived by the FAA if the applicant demonstrates that the proposed operation can be conducted safely. Waivers are available for operations over people, BVLOS, night operations (prior to the 2021 rule update), operations from moving vehicles, and others. Waiver applications are submitted through the FAA's DroneZone and require a detailed safety case. Importantly, a waiver is specific to the applicant, the sUAS, the operation, and often the geographic area — it is not a blanket permission.
Key Numbers and Rules
- 400 feet AGL — maximum altitude in uncontrolled airspace (or 400 feet above a structure within a 400-foot radius of it)
- 3 statute miles — minimum flight visibility from the control station
- 500 feet below / 2,000 feet horizontal — required cloud clearance
- Civil twilight — 30 minutes before sunrise to 30 minutes after sunset; lighting required
- 3 statute miles — anti-collision light visibility requirement during civil twilight and night
- 100 mph (87 knots) — maximum groundspeed
- Less than 55 pounds — maximum total takeoff weight for standard Part 107 sUAS
- VLOS required at all times with unaided vision
- Controlled airspace requires LAANC or DroneZone authorization
Common Test Traps
- The 400-foot structure exception is frequently misread. The drone must be within a 400-foot radius of the structure to use the exception — not merely near the structure. Altitude allowed is 400 feet above the top of the structure, not above the ground.
- Visibility is measured from the control station, not the aircraft. Test questions sometimes describe visibility from the drone's perspective or from some other reference point — always anchor your answer to where the RPIC is standing.
- Civil twilight is not the same as sunrise/sunset. Operations during civil twilight are permitted with proper lighting — but many students assume all low-light operations require a waiver. Know the 30-minute rule.
- FPV goggles alone do not satisfy VLOS. A common misconception is that watching the drone through a live video feed counts as maintaining visual line of sight. The regulation requires unaided eyes — a visual observer must maintain direct visual contact if FPV is used.
- LAANC authorization is not unlimited. LAANC provides authorization up to published UAS facility map (UASFM) altitudes, which may be 0 feet in some areas near airports. Students sometimes assume LAANC always grants the full 400 feet — always check the actual ceiling for the specific location.