By default, Part 107 says no: you may not fly over a human being unless that person is directly participating in the operation (such as the remote pilot, a person manipulating the controls, a visual observer, or a crew member needed for the operation’s safety), is located under a covered structure that can provide reasonable protection from a falling small unmanned aircraft, or is inside a stationary vehicle offering that same protection. Every other case must satisfy one of four operational categories set out in subpart D of Part 107 (the section of the federal aviation rules dedicated to flight over people). The FAA sorts these into four tiers: lighter, lower-risk aircraft qualify for the simpler categories, while heavier or higher-risk aircraft need more stringent approval before they can fly over anyone. Category 1 is the simplest: it covers any aircraft weighing 0.55 pounds or less on takeoff, including everything on board or attached, with no exposed rotating parts that would lacerate skin, such as unshielded propellers or rotors.

The other three tiers rise in what the AIRCRAFT must prove, not in what you as the pilot may intend. Categories 2 and 3 admit heavier aircraft, each keyed to an injury-severity threshold the manufacturer has demonstrated and the FAA has accepted, with Category 3 carrying the higher threshold and tighter limits on where you may fly over people. Category 4 replaces that demonstration altogether with a full airworthiness certificate issued under Part 21 — a mechanism the FAA controls directly rather than one a manufacturer declares. What each category actually demands of an aircraft, how a declaration of compliance and the category label let you know it qualifies, and the duties that fall on the remote pilot before flying over anyone are Chapter 5’s subject; the point to carry out of this chapter is that the permission comes from the aircraft’s proven safety, and never from the operation looking routine.

One restriction runs through the lighter categories too. Because the stakes are highest over dense outdoor gatherings, Categories 1, 2, and 4 still prohibit sustained flight over open-air assemblies unless the operation also meets the Remote ID conditions at § 89.110 or § 89.115(a) — two broadcast rules that both require your drone’s location and identity to go out continuously throughout the flight, and which Chapter 6 takes apart properly. Category 3, by contrast, forbids flying over an open-air assembly outright, with no Remote ID exception available. Part 107 does not itself define “open-air assembly,” so until Chapter 5 takes the term up properly, the safe working rule is to treat any dense gathering of people outdoors as potentially covered. So a 0.55-pound aircraft with no exposed blades doesn’t get a free pass over a crowd just because it clears the weight threshold — the gradient tracks one variable: how badly the aircraft could hurt the person under it, and dense outdoor gatherings raise those stakes for every category short of Category 3.

Separately, the aircraft itself must be on the books — and here new commercial pilots hit the single most common trap in the hobby-to-work transition. Recreational flying is governed by a separate federal law (49 U.S.C. 44809), which includes a small-drone registration exemption for aircraft at 0.55 pounds or less flown exclusively for recreational purposes — an exemption that does not apply to commercial flying. Part 48 — the FAA’s aircraft registration rule — covers everything else, and it requires that any aircraft flown for commercial purposes be registered, whatever it weighs. Registration costs $5.00 per aircraft, expires after 3 years unless renewed, and the assigned unique identifier — usually the registration number, or the aircraft’s own serial number if authorized by the Administrator — must be legibly displayed on an external surface of the aircraft. The logic is accountability: registration lets an aircraft found somewhere it should not be trace back to an owner.

Since September 16, 2023, a drone flown under Part 107 must also identify itself in flight. Remote ID — a broadcast of the aircraft’s identity and position — attaches to aircraft registered or required to be registered, which under Part 107 is all of them. There are three ways to satisfy it: a standard Remote ID aircraft that broadcasts on its own, a broadcast module added to an older airframe, or flying inside an FAA-recognized identification area. Which one fits your aircraft and your site, what each demands of you in the air, and what to do if the broadcast fails are Chapter 6’s subject. For now the requirement is the thing to hold: on a commercial flight the aircraft is registered and it identifies itself, and neither is optional.