Section 6: Airspace — The Classes, the Exceptions, and LAANC

Treat AGL (above ground) and MSL (above mean sea level) like feet and meters: 'you have to think about these two as units.' Sectionals print nearly everything in MSL because manned altimeters are set to sea level; drone limits (400 ft) and most airspace-class definitions are AGL - so exam questions hand you one and expect the other, bridged by field elevation. The real-world layer: a drone's displayed altitude is height above the TAKEOFF POINT - 'most people use that height as the AGL,' which terrain quietly falsifies. Flight levels (18,000+) exist but are not UAS-testable.

Controlled = Classes A through E, where ATC separates traffic; uncontrolled = Class G, 'a free-for-all.' The UAS translation: authorization required for B, C, D, and surface-primary E (E2) - nothing else. Four categories organize the whole chapter: controlled, uncontrolled, special use (Prohibited, Restricted, Warning, MOA, Alert, CFA), and 'other' (TFRs, MTRs, parachute areas, NSAs, SFRAs, parks). Class A (18,000 to FL600) exists only to be irrelevant to drones. Legal footing: Parts 71/73 define airspace - not Part 107.

CLASS B ('B for busy' - his informal hook): the upside-down wedding cake over major hubs, solid dark-blue lines, the most restrictive class - even manned pilots need explicit clearance. Only the surface-touching core cylinder concerns a 400-ft drone; the shelves floors start thousands of feet up. Altitude pairs on the chart are hundreds of feet MSL - add two zeros.

CLASS C (solid magenta): busy-but-not-B towered fields. Standard geometry: inner core 5 NM radius, surface to 4,000 AGL; outer shelf 10 NM, 1,200-4,000 AGL. Only the core needs authorization. His Albuquerque decode: chart top 9,400 MSL minus field elevation 5,355 = 4,045 AGL - 'close enough' to the definition.

CLASS D (dashed blue): one cylinder, typically 2,500 ft AGL, radius set by each airport's instrument approaches; top printed in brackets as MSL. The operational catch: part-time towers mean part-time D - after hours it REVERTS to E or G per the Chart Supplement. Worked decodes: Fort Pierce (top 25 = 2,500 MSL, elev 23, so 2,477 AGL), Prescott (75 = 7,500 MSL over 5,045 = 2,455 AGL), and nonstandard Melbourne at 1,900. Chart subtlety: a number with a trailing minus means 'up to but NOT including.'

Class E is controlled airspace defined by exclusion - whatever isn't A/B/C/D. Floors: 1,200 ft AGL nationwide by default; 700 ft AGL near many airports (magenta SHADING); the surface (dashed magenta); rarely a custom MSL 'zipper line'; and an obscure 14,500 MSL fallback. The FAA's own subtypes sort the exam question: E2 starts at the surface as an airport's PRIMARY airspace - the only Class E requiring UAS authorization. E3 and E4 also touch the surface but as EXTENSIONS of adjacent Class C or D - no authorization. E5 floats at 700.

The discrimination skill: see a dashed magenta ring, then look at what it's attached to. Adjacent dashed-blue D or solid-magenta C? It's an extension - free. Standing alone around an airport with no B/C/D? That's E2 - LAANC or DroneZone first. Decoy alert: a straight magenta line with small numbers may be a magnetic variation isogonic line, not airspace at all.

Uncontrolled, serviceless, authorization-free - and identified purely by elimination: below whatever Class E floor is charted, up to but not including it. Under a default area: surface to 1,199 AGL. Inside magenta shading: surface to 699. Under a 2,500 zipper: surface to just below 2,500 MSL. Since drones live at 0-400 AGL, most US drone flying happens here - the quiet reward for surviving Class E.

PROHIBITED (P): never - P56/P73 over Washington run 'continuous' with no controlling agency to petition. RESTRICTED (R): invisible hazards (gunfire, missiles); active/inactive by NOTAM - call the controlling agency (his Cape Canaveral example answers to Miami Center). WARNING (W): Restricted's offshore twin, 3+ NM out (W-174G: surface to FL700, 0700-2300Z). MOA: military training - not forbidden, but 'extreme caution' among fast jets and low helicopters (his example: 1,500-18,000 MSL, weekdays 0600-2100, Albuquerque Center). ALERT (A): dense flight training, strongly avoid. CONTROLLED FIRING AREA: the invisible one - never charted, because ground spotters halt the shooting when traffic appears.

TFRs are ad hoc - disasters, security scenes, VIP movement (a floating bubble follows the President), launches - issued by NOTAM, never printed on charts. The two drone-relevant standing patterns: STADIUM TFRs (NOTAM FDC 7-4319): 3 NM radius, to 3,000 AGL, one hour before through one hour after, at any 30,000+ seat venue hosting MLB, NFL, NCAA Division I football, NASCAR, IndyCar, Champ. DISNEY: 'permanent temporary flight restrictions' since ~9/11 - under 3,000 AGL within 3 NM of the Orlando and Anaheim parks.

Sourcing doctrine: tfr.faa.gov, or a live briefer at 1-800-WX-BRIEF / 1800wxbrief.com. App skepticism on record: AirMap is 'notorious' for missing stadium TFRs or inventing extras, and the B4UFLY app gets a general thumbs-down for errors.

LAANC (Low Altitude Authorization and Notification Capability) automates controlled-airspace approval: request through a provider app, and if your altitude sits at or under the pre-cleared ceiling for your grid square on the UAS FACILITY MAP, approval lands 'in about 10 seconds.' Green grids = LAANC-eligible with a printed max (100/200/400 ft); red = manual only. Coverage at recording: 700+ airports, ~80% of controlled airspace. His stack: Kitty Hawk on mobile, Skyward on desktop.

Above the grid number, or where LAANC is absent: FAA DroneZone manual authorization - officially up to 90 days, practically 'a week or two' (above-grid requests ran about a week in his experience). Boundaries to respect: COAs are a separate public-safety instrument, never mixed with Part 107 authorizations - though agencies should ask for WIDE-AREA authorizations covering whole grids.

MILITARY TRAINING ROUTES: low-level corridors; the ID length is the warning label - 3 digits = above 1,500 AGL, 4 digits = below (watch those). VFR flyways and Class B transition routes live on Terminal Area Charts, not sectionals. NATIONAL SECURITY AREAS request voluntary avoidance ('at or below 2,900 MSL' in his example) but can harden by NOTAM. The FRZ around the Capitol/White House: absolute. ADIZ: the identification border - and his practical warning about flying near the southern border at all. SFRAs: under ten nationwide, each with bespoke rules - DC (mandatory training course), LA, Hudson River, Grand Canyon, Luke AFB.

The parks rule that catches everyone: drones are MOTORIZED VEHICLES, so wilderness areas and national parks ban them completely - manned aircraft are merely 'requested' to stay 2,000 AGL up, drones just can't launch. Charted as blue line with interior dots. Grand Canyon doubles up (SFRA + park). Parachute-jump icons: not illegal, just wise to call the airport. And tethered balloons: Key West's restricted area carries an 'unmarked balloon on cable to 14,000 feet' - a cable that has killed."