When the FAA created Part 107 to govern small unmanned aircraft systems (sUAS), one of its primary goals was protecting the public from the unique risks that drones introduce into the national airspace. To accomplish that, the rule contains a set of explicit hazardous operations prohibitions — actions a remote pilot in command (Remote PIC) is flatly forbidden from performing regardless of skill level, aircraft capability, or good intentions. Understanding not only what these prohibitions are, but why the FAA put them in place and how they apply in practice, is critical for passing the Part 107 aeronautical knowledge test and for operating safely in the real world.
Unlike many areas of Part 107 that allow waivers or site-specific adjustments, the core hazardous operations rules reflect the FAA's judgment that certain behaviors carry risks too fundamental to permit without elevated scrutiny. Some of these prohibitions can be waived under 14 CFR Part 107 Subpart D, but operating under a waiver requires prior FAA approval and imposes additional conditions. Without a waiver, violation of these rules is a serious civil and potentially criminal matter.
The Core Hazardous Operations Prohibitions
Part 107.23 establishes the overarching framework: no person may operate an sUAS in a careless or reckless manner that endangers the life or property of another. Think of this as the drone equivalent of the reckless operation prohibition that applies to manned aircraft pilots. It is intentionally broad, giving the FAA flexibility to address unsafe behaviors that might not be spelled out in more specific rules.
Beyond that general careless-and-reckless standard, Part 107 contains several specific prohibitions that the FAA knowledge test frequently targets:
Operating Over Moving Vehicles and People
Under 14 CFR 107.39 and the 2021 Remote ID and Operations Over People rule, a remote pilot may not operate an sUAS directly over a human being who is not directly participating in the operation, unless the operation meets one of the four defined category standards (Category 1 through Category 4) based on aircraft weight, kinetic energy, and propeller exposure. Similarly, 107.23's careless-and-reckless prohibition effectively bars flying over moving vehicles in an uncontrolled manner that could result in a collision causing harm.
The practical takeaway: you cannot casually fly your drone over a crowd of spectators, a public street with moving cars, or a busy parking lot just because it seems safe to you. The aircraft must meet specific FAA-defined criteria, or you must have a waiver. This prohibition exists because even a relatively small sUAS can cause serious injury if it strikes a person or falls into traffic.
Dropping Objects
Part 107.23 also prohibits dropping an object from an sUAS in a manner that creates an undue hazard to persons or property on the surface or in the air. This does not mean all payload delivery is banned — it means you cannot drop items carelessly. However, a deliberate, controlled delivery of a package or other item that poses no undue hazard may be permissible. The key phrase is undue hazard: if there is a realistic risk of striking someone or damaging property, the drop is prohibited. Waivers exist for more complex delivery operations (e.g., commercial drone delivery), which require FAA approval.
Hazardous Payload
Part 107.19 requires the Remote PIC to ensure the sUAS does not carry hazardous materials as defined by the U.S. Department of Transportation. Flying a drone with explosive, flammable, corrosive, or otherwise dangerous cargo is prohibited because a crash could release those materials and cause catastrophic harm. This prohibition applies regardless of whether the flight is otherwise compliant with Part 107.
Operating From a Moving Vehicle or Aircraft
Under 14 CFR 107.25, operating an sUAS from a moving vehicle or aircraft is generally prohibited. There are exceptions: operation from a moving land vehicle is allowed over a sparsely populated area if the sUAS is not carrying another person's property for compensation, and operation from a moving water-borne vehicle is allowed over a sparsely populated area as well. This rule prevents situations where the unpredictable movement of the launch platform compounds the already challenging task of maintaining situational awareness and aircraft control. A remote pilot in a moving car, for instance, cannot reliably maintain visual line of sight (VLOS) and react appropriately to unexpected hazards.
Operating Under the Influence
Part 107.27 applies the same alcohol and drug prohibitions that govern manned aircraft pilots. A remote pilot may not act as Remote PIC or manipulate the controls of an sUAS within 8 hours after consuming alcohol (the "bottle to throttle" standard), while under the influence of alcohol, with a blood alcohol concentration at or above 0.04 percent, or while using any drug that affects faculties in a way that is contrary to safety. The FAA may also require a Remote PIC to submit to testing for alcohol or drugs under certain circumstances.
Careless or Reckless Operation
As mentioned, 107.23's broad prohibition on careless or reckless operation is a catch-all. Courts and the FAA have interpreted similar language in manned aviation broadly. Flying at low altitude near bystanders for no operational reason, intentionally startling animals or people, or conducting stunts that risk loss of control could all qualify as careless or reckless even if no specific rule explicitly names that maneuver.
Why These Prohibitions Matter
The hazardous operations rules exist because the consequences of a drone mishap extend far beyond the operator. A small commercial drone weighing just a few pounds traveling at speed carries enough kinetic energy to cause serious lacerations, eye injuries, or blunt-force trauma. A heavier sUAS can cause fatal injuries. In the context of moving vehicles, a collision that causes a driver to lose control can trigger a chain of events injuring many people. The FAA's prohibition framework attempts to hold these risks to an acceptable minimum while still permitting the broad range of legitimate commercial and recreational operations that make Part 107 valuable.
There is also a systemic safety concern: a high-profile drone accident can result in new restrictive regulations that harm the entire industry. Every Remote PIC who follows the hazardous operations rules helps protect not just the public, but the future of commercial drone operations.
Key Numbers and Rules
- 8 hours — minimum time between last alcohol consumption and acting as Remote PIC (107.27).
- 0.04% BAC — the maximum allowable blood alcohol concentration while operating (107.27).
- Undue hazard — the standard for prohibited object drops under 107.23; the key word is "undue," meaning unnecessary or unreasonable risk.
- Moving vehicle exception — operating from a moving land or water-borne vehicle is permitted over a sparsely populated area, subject to conditions (107.25).
- Category 1–4 — the Operations Over People categories established in the 2021 rule that govern when you may fly over non-participating humans; each category has specific aircraft weight and design requirements.
- Waivers (Subpart D) — certain hazardous operation prohibitions may be waived with prior FAA approval if the applicant demonstrates equivalent level of safety.
Common Test Traps
- The "8-hour rule" isn't the only alcohol restriction. Students often memorize the 8-hour bottle-to-throttle rule and miss that you also cannot operate if your blood alcohol exceeds 0.04% or if you are impaired — even if 8 hours have passed since your last drink.
- Object drops are not automatically illegal. The rule prohibits drops that create an undue hazard, not all drops. A carefully controlled, risk-mitigated delivery may be permissible. Test questions sometimes present a scenario expecting you to know the standard is "undue hazard," not a blanket ban.
- Moving vehicle prohibition applies in populated areas. The exam may present a scenario where a pilot launches from a boat on an open lake in a rural area and ask if that is legal — it is, under the exception for moving watercraft in sparsely populated areas. Many students miss this exception.
- Careless and reckless is subjective but real. The FAA does not have to point to a specific broken rule to enforce a careless-and-reckless violation. Operating in a way that a reasonable pilot would find unsafe is enough. Do not assume an action is legal simply because it doesn't violate a precisely numbered rule.
- Waiver does not equal blanket permission. Some students think obtaining any waiver allows them to conduct broadly unsafe operations. A waiver is specifically scoped — it only allows the particular deviation described in the approval, under the conditions the FAA set, and does not suspend the careless-and-reckless standard.
Mastering the hazardous operations prohibitions gives you a solid foundation not just for the knowledge test, but for the real-world judgment that keeps the public safe and keeps your certificate intact. When in doubt, ask whether a reasonable observer would call your planned operation careless or reckless — if the answer is yes, find another way or seek a waiver before you fly.