One of the most significant regulatory expansions in recent FAA rulemaking for small unmanned aircraft systems (sUAS) is the framework governing operations over human beings and moving vehicles. For years after Part 107's original publication, flying a drone directly over people who were not involved in the operation was effectively prohibited without a waiver. The FAA later codified a tiered, risk-based approach under 14 CFR Part 107 Subpart D, which allows certain operations over people and moving vehicles without a waiver — provided the drone meets specific design and operational standards. Every Remote Pilot Certificate candidate needs to understand this framework thoroughly, both for the knowledge test and for safe real-world operations.
It is important to distinguish between two related but separate concepts from the start. Operations over people refers to flight where the drone is directly overhead of human beings who are not involved in the operation. Operations over moving vehicles refers to sustained flight over active roadways, parking lots, or waterways where vehicles are in motion. The rules for each scenario are connected but have some distinct requirements.
The Four Category Framework
Part 107 divides operations over people into four categories — Category 1, 2, 3, and 4 — based primarily on the drone's kinetic energy at impact, its design, and any remote ID or Declaration of Compliance requirements. The higher the category number, the more capable and complex the operation permitted, but also the more demanding the compliance requirements.
Category 1
Category 1 is the simplest tier. A drone qualifies if it weighs 0.55 pounds (250 grams) or less at takeoff, including everything on board. No exposed rotating parts that could lacerate human skin are permitted. Because the kinetic energy at impact for such a small aircraft is considered inherently low, no FAA Declaration of Compliance or special airworthiness certification is required. The remote pilot simply ensures the drone meets the weight limit. Many consumer micro-drones fall into this category. Operations over any number of people not involved in the operation are permitted under Category 1.
Category 2
Category 2 allows flight over people with drones that weigh more than 0.55 pounds, provided the drone has been designed and tested to limit the transfer of injury-causing kinetic energy in a collision. Specifically, the drone must be shown — through testing protocols accepted by the FAA — to cause no more than 11 foot-pounds of force on human tissue upon impact. Additionally, the drone must not have any exposed rotating parts that could lacerate skin, and it cannot be operated in a way that creates an undue hazard. The manufacturer must submit a Declaration of Compliance to the FAA, and the drone must appear on the FAA's accepted list. Operations over open-air assemblies of people (crowds) are not permitted under Category 2.
Category 3
Category 3 permits a higher level of kinetic energy at impact — up to 25 foot-pounds of force — but with significantly greater operational restrictions to compensate for the increased risk. Like Category 2, the drone must carry a valid Declaration of Compliance and appear on the FAA's accepted list, and no exposed rotating parts that can lacerate are allowed. The key operational restrictions for Category 3 are: the drone may not fly over open-air assemblies of people at all, and when operating over people who are not part of the operation, the remote pilot must ensure those people are within a restricted-access site where everyone present has been notified that a drone may fly overhead. This notification requirement is critical — it transforms bystanders into people who have, in effect, accepted the presence of the UAS. A Category 3 drone can fly over a small group of workers in a fenced construction zone, for example, if those workers have been told the drone will be operating above them.
Category 4
Category 4 is the highest tier and is specifically designed for aircraft that hold an FAA airworthiness certificate issued under Part 21. The drone must be operated in accordance with the operating limitations of that airworthiness certificate. Because an airworthiness certificate imposes its own rigorous standards, the FAA considers this level of design oversight sufficient to permit flight over people, including in more flexible circumstances. Category 4 drones are currently rare in the small commercial UAS world, as obtaining Part 21 airworthiness certification is a demanding process typically associated with traditional manned aircraft.
Operations Over Moving Vehicles
Part 107 also addressed a longstanding grey area: flying over active roads, highways, and other areas where vehicles are in motion. The rule distinguishes between sustained flight over moving vehicles and incidental crossing. Under §107.145, sustained flight over moving vehicles is permitted only when the operation occurs over people located within a closed- or restricted-access site who are inside a stationary vehicle (and who have been notified that a small UAS may fly over them), or when the operation takes place in a sparsely populated area and does not sustain flight over any moving vehicle outside those conditions. This is a narrower standard than simply meeting the Category 1, 2, 3, or 4 design requirements for overflight of people — the moving-vehicle provisions of §107.145 impose their own specific conditions in addition to category compliance. The rational basis is straightforward: a drone that fails over a moving vehicle poses a risk to the vehicle's occupants and anyone nearby.
There is an important nuance: operations over moving vehicles are allowed without a waiver only in sparsely populated areas or when the roadway has been secured. If a remote pilot needs to sustain flight over a congested highway or an urban street full of moving traffic, that scenario may require coordination with local authorities to secure the area or, in some cases, a Part 107 waiver. Remote pilots must evaluate the environment carefully. Flying briefly across a rural road while the shot clears is a different risk profile than hovering over a packed urban intersection.
Why This Framework Matters
The practical importance of this framework is enormous for commercial remote pilots. Real estate photography, infrastructure inspection, news gathering, and film production all routinely put drones near or over people. Before this rule, any such operation over uninvolved people required a lengthy waiver process. Now, a pilot with a compliant Category 1 or Category 2 drone can legally perform many common commercial missions without a waiver. However, the burden is on the remote pilot to verify the drone's category before the flight — the FAA places responsibility squarely on the pilot, not the manufacturer's marketing materials.
Safety is the underlying principle throughout. The kinetic energy thresholds were derived from FAA research into blunt force trauma, and the laceration risk standards reflect the particular danger of spinning propeller blades. A drone that seems small can still cause a serious eye or scalp injury at close range, which is why even Category 1 prohibits exposed rotating parts that could lacerate.
Key Numbers and Rules
- Category 1: 0.55 lbs (250 g) or less at takeoff; no lacerating exposed parts; no Declaration of Compliance required; can fly over any people not in the operation.
- Category 2: Over 0.55 lbs; must not exceed 11 ft-lbs impact force; Declaration of Compliance required; cannot fly over open-air assemblies.
- Category 3: Over 0.55 lbs; must not exceed 25 ft-lbs impact force; Declaration of Compliance required; restricted-access site with prior notification required; no open-air assemblies.
- Category 4: Must hold an FAA airworthiness certificate (Part 21); operated per that certificate's operating limitations.
- Moving vehicles: Under §107.145, sustained overflight is permitted only over people in stationary vehicles within a notified closed- or restricted-access site, or in sparsely populated areas; use in congested areas may require the area to be secured or a waiver.
- Open-air assemblies: Prohibited under Category 2 and Category 3; Category 1 technically permits it, though pilots must still manage overall safety and hazard risk.
- Declaration of Compliance: Required for Categories 2 and 3; submitted by manufacturer to FAA; drone must appear on FAA's accepted list before operations begin.
Common Test Traps
- Confusing weight and category: Many students assume that any drone under 0.55 lbs automatically qualifies for operations over people in all scenarios. Category 1 does permit this, but only if the drone also has no exposed rotating parts that could lacerate — weight alone is not the sole criterion.
- Mixing up kinetic energy limits: Category 2 is 11 foot-pounds; Category 3 is 25 foot-pounds. Students frequently swap these values on the exam. Remember: higher category number, higher allowed energy, but more operational restrictions.
- Open-air assemblies confusion: Some students believe Category 3 permits flights over crowds if the crowd is notified. It does not. Open-air assemblies of people are prohibited under both Category 2 and Category 3, full stop.
- Who bears compliance responsibility: The remote pilot in command is responsible for verifying the drone's category before flight. Relying only on what the manufacturer's box says, without checking the FAA's Declaration of Compliance list, is not sufficient legal protection.
- Moving vehicles in sparse vs. congested areas: The exam may present scenarios where flight over moving vehicles appears straightforward. Always consider whether the area qualifies as sparsely populated or secured — sustained flight over dense, active traffic without proper controls is not automatically permitted even with a compliant drone.