Airspace Classifications, Weather Minimums, and Operational Requirements

Comprehensive vocabulary flashcards covering Class G, D, C, B, and E airspace dimensions, entry procedures, cloud clearances, weather minimums, and equipment requirements.

Class G Day Weather Minimums ($\le 1,200'$ AGL)

Requires $1\text{ SM}$ visibility and clear of clouds, with helicopters permitted $1/2\text{ SM}$.

Class G Night Weather Minimums ($\le 1,200'$ AGL)

Requires $3\text{ SM}$ visibility, $1,000'$ above, $500'$ below, and $2,000'$ horizontal cloud clearance, with an exception allowing $1\text{ SM}$ and clear of clouds within an airport traffic pattern under 14 CFR 91.155(b)(2).

Class G Day Weather Minimums ($> 1,200'$ AGL but $< 10,000'$ MSL)

Requires $1\text{ SM}$ visibility and standard 152 cloud clearance ($1,000'$ above, $500'$ below, and $2,000'$ horizontal).

Class G Night Weather Minimums ($> 1,200'$ AGL but $< 10,000'$ MSL)

Requires $3\text{ SM}$ visibility and standard 152 cloud clearance ($1,000'$ above, $500'$ below, and $2,000'$ horizontal).

Class G High Altitude Weather Minimums ($\ge 10,000'$ MSL and $> 1,200'$ AGL)

Requires $5\text{ SM}$ visibility and "111" cloud clearance ($1,000'$ above, $1,000'$ below, and $1\text{ SM}$ horizontal).

Class D Charting Box

A two-digit dashed blue box indicating the ceiling in hundreds of feet MSL, where a minus sign [-] denotes "up to but not including" (e.g., [-30] means up to $2,999\text{ feet}$ MSL).

Class D Weather Minimums

The standard "3-152" rule requiring $3\text{ SM}$ visibility, $1,000'$ above, $500'$ below, and $2,000'$ horizontal cloud clearance.

Special VFR (SVFR)

A flight clearance requiring $1\text{ SM}$ visibility and clear of clouds; at night under 14 CFR 91.157, the pilot must be instrument-rated and the aircraft must be IFR-capable.

Class C Weather Minimums

The standard "3-152" VFR minimums consisting of $3\text{ SM}$ visibility, $500'$ below, $1,000'$ above, and $2,000'$ horizontal cloud clearance.

Class C Standard Dimensions

A blueprint consisting of a $5\text{ NM}$ core from the surface to $4,000'$ above airport elevation, a $10\text{ NM}$ shelf from $1,200'$ to $4,000'$ above airport elevation, and a surrounding $20\text{ NM}$ procedural Outer Area.

Class C Two-Way Radio Contact

Communication established per AIM 3-2-4 when an air traffic controller reads back the pilot's call sign, which authorizes entry into Class C airspace.

Class C Equipment Requirements

Mode C (or Mode S) transponder and ADS-B Out mandated by 14 CFR 91.215 and 91.225 within and above Class C airspace up to $10,000\text{ feet}$ MSL.

Class Bravo (Class B) Airspace

Regulatory, highly controlled airspace surrounding the nation’s busiest airports in passenger enplanements and total IFR operations, shaped like an upside-down wedding cake.

Class B Basic VFR Weather Minimums

A requirement of $3\text{ statute miles}$ visibility and clear of clouds per 14 CFR 91.155.

Class B Lateral and Vertical Limits

Typically extends laterally $20\text{ or }30\text{ NM}$ from the primary airport, starting at the surface and extending up to a ceiling normally of $10,000\text{ feet}$ MSL (or $12,000\text{ feet}$ MSL or higher at high-elevation airports).

Class B Entry Clearance

A mandatory explicit ATC instruction per 14 CFR 91.131(a)(1) where the controller must state the aircraft's tail number and say the exact phrase "Cleared to enter Class Bravo airspace."

Class B Pilot Certification Requirements

Requires the pilot-in-command to hold at least a Private Pilot Certificate or a Sport/Recreational certificate with endorsements; student pilots require an endorsement within the preceding 90 days and are prohibited from 12 high-density airports listed in Part 91 Appendix D.

Mode C Veil

A $30\text{ NM}$ radius area defined in 14 CFR 91.215(b)(2) extending from the surface up to $10,000'$ MSL around primary Class B airports where an operative Mode C/S transponder and ADS-B Out are mandatory, even under Class B shelves.

Class E Surface Area

Controlled airspace surrounding non-towered airports with instrument procedures, depicted on charts with a dashed magenta line, requiring a two-way radio and specific weather minimums.

Class E Surface Area Extensions

Rectangular or lateral extensions attached to Class B, C, D, or E surface areas designed to protect arrival and departure flight paths.

Class E Transition Areas

Airspace designated around airports with instrument approaches beginning at $700\text{ feet}$ AGL, charted by a faded/shaded magenta vignette.

Class E En Route / Standard Airspace

Airspace extending across almost all of the United States from $1,200\text{ feet}$ AGL up to, but not including, $14,500\text{ feet}$ MSL or overlying airspace.

Class E High Altitude Airspace

Airspace covering the contiguous U.S. and Alaska from $14,500\text{ feet}$ MSL to $18,000\text{ feet}$ MSL, and occurring again above Flight Level 600 (FL600).

Class E ADS-B Out Requirement

Mandatory equipment operation at and above $10,000\text{ feet}$ MSL (excluding airspace at or below $2,500\text{ feet}$ AGL) and above $3,000\text{ feet}$ MSL in the Gulf of Mexico within $12\text{ miles}$ of the coast.