UA.I.B.K25: Night operations.

ACS Area I — Regulations Task B: Operating Rules References: 14 CFRCode of Federal RegulationsCloseThe federal rulebook where Part 107, Part 89, Part 48, and other aviation rules live. parts 47, 48, 89, and 107, subpart B; ACAdvisory CircularCloseFAA guidance that explains acceptable ways to comply with rules or understand FAA procedures. 107-2; FAAFederal Aviation AdministrationCloseThe U.S. aviation regulator responsible for Part 107 rules, airspace, and pilot certification processes.-H-8083-25; FAAFederal Aviation AdministrationCloseThe U.S. aviation regulator responsible for Part 107 rules, airspace, and pilot certification processes.-G-8082-22

Key Concepts

Defining Night and Civil Twilight

Night is defined as the time between the end of evening civil twilight and the beginning of morning civil twilight, as per § 1.1 and The Air Almanac. In the continental U.S., evening civil twilight is from sunset to 30 minutes after sunset, and morning civil twilight is from 30 minutes before sunrise to sunrise. In Alaska, civil twilight times differ and are detailed in The Air Almanac. Customized sunrise/sunset and twilight tables can be obtained from the U.S. Naval Observatory. For exams and flight planning, accurately determine when civil twilight ends and night begins at your location and date, as these times dictate lighting and operational requirements under part 107.^[1]

Lighting Requirements During Civil Twilight

During civil twilight, small unmanned aircraft must have anti-collision lighting visible for at least 3 statute miles (sm). Ensure your equipment meets this visibility requirement when flying between sunset and 30 minutes after sunset, or between 30 minutes before sunrise and sunrise, in the continental U.S. Plan for power and maintenance of anti-collision lighting, confirm performance before launch, and verify local twilight times to ensure lighting is active throughout the civil twilight period.^[1]

Human Factors and Crew Coordination at Night

Night operations increase human-factor risks. Illness or medications that impair situational awareness can make a remote PICRemote Pilot in CommandCloseThe certificated remote pilot responsible for the Part 107 operation., person manipulating the controls, or visual observer (VOVisual ObserverCloseA person who helps the remote PIC see and avoid hazards during a drone operation.) unfit for duty. Conditions like migraines or significant pain can also impair performance. Any hearing or speaking impairment affecting communication must be mitigated by alternative means, such as sign language. Night crews should brief communication methods, ensure everyone is medically and cognitively fit, and avoid starting a night flight if any crewmember’s condition could compromise scanning, decision-making, or crew coordination.^[1]

Part 107 Rules That Still Matter at Night: Preflight, People, and Vehicles

• Preflight Inspection: Required under part 107, the remote pilot in command (PICPilot in CommandCloseThe person responsible for the flight. Under Part 107, this is usually the remote pilot in command.) must conduct a preflight inspection to ensure the small unmanned aircraft is safe for operation. This requirement remains unchanged for night operations, but risk increases after dark, necessitating disciplined preflight planning and inspection to manage unseen hazards.^[4]

• Operations Over People: Part 107's rules for operations over people apply in low-light environments. Category 1 operations are for small unmanned aircraft weighing 0.55 pounds (250 grams) or less. Know your aircraft’s eligibility and limitations before considering over-people operations near night events or venues.^[3]

• Restrictions Over Moving Vehicles: These apply regardless of lighting conditions. If not within or over a closed- or restricted-access site, the small unmanned aircraft must not maintain sustained flight over any moving vehicle; only transit is allowed for Categories 1–3 over non-participants. Plan night routes to avoid roadways and time any unavoidable crossings as brief transits.^[3]

• Open-Air Assemblies: Category 3 eligible small unmanned aircraft must not operate over open-air assemblies of human beings (§ 107.125(b)). Other categories prohibit sustained flight over open-air assemblies unless certain requirements in § 89.110 or § 89.115(a) are met. Consider these constraints in night mission planning around concerts, stadiums, or similar gatherings.^[7]

• Manufacturer’s Instructions: Follow the manufacturer’s remote pilot operating instructions and ensure they are current. These instructions provide necessary configuration details for compliance, but the remote PICRemote Pilot in CommandCloseThe certificated remote pilot responsible for the Part 107 operation. is responsible for determining safe operational parameters, including those unique to night conditions.^[8]