Section 3: Regulation — Part 107 Front to Back, with Every Number the Exam Wants

Three legal doors into US airspace with a drone: Part 107 (the umbrella), 49 USC 44809 (the recreational exemption - all EIGHT conditions or it doesn't apply), and COAs for public agencies. Because recreation is an exemption, failing any one condition silently drops you into Part 107 rules without a certificate - the Philadelphia case ended at $182,000 in fines. Intent, not money, defines recreational status: paid AFTER spontaneously filming an avalanche is still recreational; launching TO make content is not.

The map: Title 14 CFR is the FAA's book (Title 49 is transportation/NTSB); Part 107's subparts run A (general), B (operating rules), C (certification), D (operations over people - added 2021), E (waivers).

FAA validity periods count CALENDAR months: find the target month, then run to its last day, 11:59 pm. Issued Oct 7 + 24 calendar months = valid through Oct 31 two years later. A 6-calendar-month document issued May 4 runs to Nov 30. The exam hands you an issue date and asks the expiration - the trap is adding literal months instead of rounding to month-end. Applies across certificates, waivers, and most FAA paperwork; the notable exception is aircraft REGISTRATION, a literal 3-year term.

Small UAS = weighs LESS than 55 lbs at takeoff with everything attached (exactly 55 is out). The famous 250-gram registration exemption belongs to RECREATIONAL flyers only - under Part 107 there is no weight floor; every aircraft registers. The three humans: the UNMANNED AIRCRAFT is defined by no possibility of onboard intervention; the VISUAL OBSERVER assists the RPIC in seeing and avoiding; the REMOTE PILOT IN COMMAND manipulates the controls or supervises - and holds final authority. Delivery-for-hire is not Part 107 at all - air-carrier drone operations live in Part 135.

Carry: certificate, photo ID (the certificate has no photo), and operation-specific documents (registration, waiver, means-of-compliance for over-people work). Since 2021 the show-me list includes not just FAA and NTSB but state/local/federal law enforcement and TSA. Falsifying anything: denial, suspension, revocation, or civil penalty.

The FAA accident clock: report within 10 CALENDAR days when there's serious injury, loss of consciousness, or damage OVER $500 to someone ELSE'S property - your own broken drone never counts. The NTSB clock (49 CFR 830) is separate, stricter, and IMMEDIATE: death or serious injury (their definition: >48h hospitalization within 7 days, fractures beyond minor, organ damage, serious burns), flight-control failure, in-flight fire or collision, or third-party damage over $25,000. Same incident, both regimes, independently.

No crew member acts within 8 hours of drinking ('8 hours bottle to throttle'), while impaired, on impairing drugs, or at blood/breath alcohol of 0.04 OR GREATER - each condition independently disqualifying. Refusing a test (or not furnishing results within 4 hours) can deny an application for up to a year or revoke EVERY pilot certificate you hold. A drug/alcohol conviction bars certification up to a year from final conviction. And 91.19 bans carrying narcotics, marijuana, depressants, or stimulants aboard the aircraft at all.

NIGHT (post-2021): between evening and morning civil twilight you may fly with (1) night training - automatically covered if your knowledge test came after March 1, 2016 - and (2) an anti-collision light visible for at least 3 STATUTE MILES with an anti-collision flash rate (intensity may be dialed down when the PIC judges it safer). Civil twilight itself - roughly the 30 minutes past sunset and before sunrise - needs only the light.

VLOS (107.31): the RPIC and any VO must see the aircraft UNAIDED - corrective lenses fine, binoculars and telescopes banned - tracking position, attitude, altitude, direction, traffic, and hazards. Which is why FPV is never self-sufficient: goggles aren't unaided eyes on the aircraft, so an FPV flight legally requires a visual observer. VO rules: effective communication with the pilot, unaided visual contact, coordinated scanning. And 107.35's ratio: one aircraft flown, one aircraft observed, per person, at a time.

107.51's ceiling is 400 feet ABOVE GROUND LEVEL, following the topography - he quotes the FAA final rule: the limit applies 'above the ground... over which it is flying,' REGARDLESS of terrain. Controller altitude is takeoff-relative and therefore lies whenever the ground isn't flat; his worked examples show legal flights displaying 600 and violations displaying 350. He calls out competing instructors teaching this wrong.

The STRUCTURE exception: within a 400-foot horizontal radius of a structure you may climb to 400 feet above its uppermost point - in UNCONTROLLED airspace only. Then the minimums to memorize as a block: clouds - 500 feet below, 2,000 feet horizontal; visibility - 3 statute miles; speed - 100 mph or 87 knots (learn both; the exam asks in either unit). And 107.37 gives the drone permanent last place: yield right-of-way to ALL other aircraft, always - 'you're not forcing other aircraft from changing their intended flight path.'

Eligibility: 16+, English, pass the in-person initial knowledge test. Passing plus the free online application yields a temporary certificate valid 120 days; plastic arrives in 30-40 days. Fail and you wait 14 days to retake. RECURRENCY changed March 1, 2021: every 24 calendar months you complete free online recurrent training at FAAsafety.gov - no new IACRA application, just keep the completion certificate. Pre-2021 material describing a $160 recurrent TEST is obsolete. Housekeeping with teeth: report address changes within 30 days (107.77) - 'one of the most commonly violated rules.'

Since April 2021, over-people and over-moving-vehicle flight requires a Subpart D category; without one, the old 107.39 rule stands: only over direct participants, people under cover, or in stationary vehicles. The vocabulary does the legal work: SUSTAINED flight (hovering, circling, passes over a crowd) vs incidental TRANSIT, and 'open-air assembly' - which 'the FAA has declined to define,' offering examples instead (concerts, parades, protests, festivals, packed beaches - but not scattered shoppers or a family on a trail).

The ladder: CATEGORY 1 - under 250g with no lacerating exposed rotors, self-certified, no paperwork; sustained flight over assemblies demands Remote ID. CATEGORY 2 - impact energy <= 11 ft-lb, no lacerating parts, labeled, listed on an FAA Declaration of Compliance. CATEGORY 3 - <= 25 ft-lb, same paperwork, but NEVER over open-air assemblies; over people only at closed-access sites with everyone notified, or per the base rule. CATEGORY 4 - a genuine Part 21 airworthiness certificate plus a maintenance program: manned-aircraft-grade. The trap he flags: DOC listing has two filters - a drone listed for Remote ID (like the Mavic Pro Platinum) is NOT thereby approved for over-people. Filter by 'OOP.'

REGISTRATION (Part 48): $5, at FAA DroneZone, full stop - the $30-50 third-party sites are scams. Recreational: $5 covers the person and all their aircraft; Part 107: $5 per aircraft. Valid 3 years, renewable 6 months early; markings legible on the EXTERIOR (since Feb 2019); ownership/address updates within 14 calendar days - a different clock than the pilot certificate's 30. Under-13 owners register through a parent; foreign-registered aircraft can't dual-register.

REMOTE ID (Part 89, enforced from September 2023): required for anything that must be registered - so all Part 107 aircraft, and recreational craft over 250g. Three paths: Standard (built-in broadcast: aircraft AND control-station position, once a second, over Wi-Fi/Bluetooth), a strap-on Module (broadcasts aircraft position + only the TAKEOFF point), or flying inside a FRIA. Not ADS-B - that's manned aviation's system, and transponders are banned on drones; DJI AirSense only RECEIVES. The public sees position through apps; your name and address stay FAA-gatekept for law enforcement.

WAIVERS (Subpart E): 107.205 lists what bends - moving vehicles, the light rule, VLOS, VO, multiple aircraft (drone light shows live here), right-of-way, over-people, and the 107.51 limits. What is NOT on the list: 107.41 controlled airspace - that's an AUTHORIZATION, a different process through the same FAA DroneZone door. Conflating them is a classic error.