Compare Military Operations Areas (MOAs), Alert Areas, and Warning Areas on Sectional Charts.

MOAs separate military training activities from IFR traffic; VFR pilots may enter without clearance but should exercise extreme caution and contact the controlling agency. Alert Areas contain a high volume of pilot training or unusual aerial activity where all participating and transiting pilots share responsibility for collision avoidance. Warning Areas extend from 3 NM outward from the U.S. coast over international waters and contain hazards similar to Restricted Areas.

On an FAA VFR Sectional Chart, what does a star (*) above the airport beacon symbol indicate, and what indicates a right-hand traffic pattern?

A star beside the airport symbol indicates a rotating airport beacon operates from sunset to sunrise (an asterisk inside the airport data block indicates part-time or pilot-controlled beacon operation). 'RP' followed by runway numbers in the airport data block indicates a non-standard Right Traffic Pattern for those specific runways (standard pattern is left-hand turns).

What are the vertical limits, operating rules, and altimeter setting requirements for Class A airspace?

Class A airspace extends from 18,000 feet MSL up to and including FL600 over the 48 contiguous states and Alaska (within 12 NM of the coast). All operations must be conducted under Instrument Flight Rules (IFR) with an IFR clearance, an Instrument-rated pilot, and the altimeter set to standard pressure (29.92" Hg).

How are Runway Edge Lights, Taxiway Edge Lights, and Runway Threshold Lights color-coded at night?

Runway Edge Lights are white, except on instrument runways where the last 2,000 feet (or half the runway length, whichever is less) are yellow (amber) to form a caution zone. Taxiway Edge Lights are blue (Taxiway Centerline lights are green). Runway Threshold Lights are green facing approaching aircraft and red facing the departure end.

Compare the VFR visibility and cloud clearance minimums in Class E airspace below 10,000 feet MSL versus at or above 10,000 feet MSL.

Below 10,000 feet MSL: 3 SM visibility, 500 feet below, 1,000 feet above, and 2,000 feet horizontal from clouds (3-5-1-2). At or above 10,000 feet MSL (and more than 1,200 ft AGL): 5 SM visibility, 1,000 feet below, 1,000 feet above, and 1 statute mile horizontal from clouds (5-1-1-1) due to higher closure speeds of aircraft above the 250-knot speed limit.

What is a Controlled Firing Area (CFA), and how is it depicted on an aeronautical chart?

A CFA contains hazardous ordnance activities that are immediately suspended whenever spotter aircraft, radar, or ground lookout personnel detect an approaching aircraft. Because the activity ceases rather than requiring aircraft to deviate, CFAs are NOT depicted on aeronautical charts.

What are the VFR weather minimums in Class G airspace above 1,200 feet AGL, both below and above 10,000 feet MSL?

More than 1,200 feet AGL but less than 10,000 feet MSL: Day requires 1 SM visibility and 500 ft below, 1,000 ft above, 2,000 ft horizontal; Night requires 3 SM visibility and 500/1,000/2,000 ft. More than 1,200 feet AGL and at or above 10,000 feet MSL (Day or Night): 5 SM visibility and 1,000 ft below, 1,000 ft above, and 1 SM horizontal (5-1-1-1).

What are the VFR weather minimums in Class G (uncontrolled) airspace during the Day vs. Night at or below 1,200 feet AGL?

Day at or below 1,200 feet AGL: 1 SM flight visibility and Clear of Clouds. Night at or below 1,200 feet AGL: 3 SM flight visibility and 500 feet below, 1,000 feet above, and 2,000 feet horizontal from clouds (3-5-1-2). Exception: In an airport traffic pattern at night within 1/2 mile of the runway, 1 SM and Clear of Clouds is permitted if remaining below 1,200 ft AGL.

Distinguish between a Displaced Threshold and a Relocated Threshold (Blast Pad / Stopway with yellow chevrons).

A Displaced Threshold (marked by white arrows leading up to a white threshold bar) may be used for taxiing, takeoff roll, and rollout after landing from the opposite direction, but NOT for landing touchdown. A Blast Pad / Stopway (marked by large yellow chevrons) is not usable for any normal ground operations (no taxi, takeoff, or landing), except for emergency rollout stopping.

For Class C and Class D airspace entry, what ATC response constitutes 'establishing two-way radio communications' versus being prohibited from entering?

Two-way radio communication is established if the controller responds to the initial radio call using the aircraft's specific callsign (even if the controller says '[Aircraft Callsign], standby'). If the controller responds only with 'Aircraft calling [Approach/Tower], standby' without stating the callsign, the pilot may NOT enter the airspace.

How is Maximum Elevation Figure (MEF) calculated on a Sectional Chart quadrant, and how is it depicted?

The MEF is shown in thousands and hundreds of feet (e.g., 12^5 = 12,500 feet MSL) within each 30-minute latitude by 30-minute longitude quadrangle. It is calculated by taking the highest known terrain or man-made obstacle in the quadrant, adding 100 feet for vertical error (plus 200 feet for uncharted obstacles if based on terrain), and rounding up to the next higher 100-foot level.

What is a Runway Incursion, and what is marked by a dashed circle/ellipse labeled 'HS 1' on an FAA Airport Diagram?

A Runway Incursion is any occurrence at an aerodrome involving the incorrect presence of an aircraft, vehicle, or person on the protected area of a surface designated for the landing and takeoff of aircraft. 'HS 1' marks a Runway Safety 'Hot Spot'—a complex or confusing taxiway/runway intersection with a history of surface incidents requiring heightened pilot situational awareness.

What are the standard dimensions, charting depiction, and VFR weather minimums for Class D airspace?

Class D extends from the surface to 2,500 feet AGL (converted to MSL and shown in a dashed blue box, e.g., [25] for 2,500 ft MSL) around airports with an operating control tower, depicted by a dashed blue line. VFR minimums are 3 SM flight visibility and 500 feet below, 1,000 feet above, and 2,000 feet horizontal from clouds ('3-5-1-2').

Distinguish between Prohibited Areas and Restricted Areas in Special Use Airspace.

Prohibited Areas (e.g., P-40 Camp David, P-56 White House) forbid flight by all aircraft at all times for national security reasons. Restricted Areas (e.g., R-2508) contain unusual, often invisible hazards to aircraft (such as artillery firing, aerial gunnery, or guided missiles); VFR flight is permitted only during inactive hours or with explicit authorization from the controlling agency.

What are the ATC Light Gun Signals for an aircraft In Flight versus On the Ground for Flashing Red, Flashing White, and Alternating Red and Green?

Flashing Red: Airport unsafe, do NOT land (In Flight) / Taxi clear of the runway in use (On Ground). Flashing White: Not applicable in flight / Return to starting point on airport (On Ground). Alternating Red and Green: Exercise extreme caution (both In Flight and On the Ground).

What are the requirements to fly through an Air Defense Identification Zone (ADIZ) under VFR?

An operational two-way radio, an operating altitude-encoding transponder (Mode C/S) on a discrete ATC-assigned squawk code, and an active Defense VFR (DVFR) flight plan filed prior to penetration with an estimated time and point of ADIZ penetration (which must be adhered to within +/- 5 minutes and 10–20 NM).

What are the weather minimums and pilot/aircraft requirements for a Special VFR (SVFR) clearance in a controlled surface area?

Weather minimums: At least 1 SM flight visibility and Clear of Clouds (helicopters have no minimum visibility requirement). Pilot must specifically request SVFR (ATC cannot offer it). For SVFR operations between sunset and sunrise (Night), the pilot MUST hold an Instrument Rating and the aircraft MUST be equipped for IFR flight under 14 CFR 91.205(d).

What is the Mode C / ADS-B Out Veil surrounding a Class B primary airport?

An airspace cylinder extending 30 nautical miles (NM) from the primary Class B airport from the surface up to 10,000 feet MSL (depicted by a thin solid magenta circle on Sectional Charts). Within this veil, all aircraft must be equipped with an operable Mode C or Mode S altitude-encoding transponder and 14 CFR 91.225 ADS-B Out (unless flying an aircraft originally certificated without an engine-driven electrical system).

When an airport's Class D or Class C control tower closes for the night, what does the surface airspace revert to?

It typically reverts to either Class E surface area (if continuous weather reporting and instrument approaches remain active) or Class G uncontrolled airspace, as specified in the Chart Supplement U.S. (formerly A/FD).

How do airport Runway Holding Position Signs, Taxiway Location Signs, and Taxiway Direction Signs differ in color scheme?

1. Mandatory Instruction / Runway Holding Position Signs: White inscriptions on a RED background; 2. Taxiway Location Signs (indicating the taxiway or runway you are currently on): Yellow inscriptions on a BLACK background with a yellow border; 3. Taxiway Direction Signs (indicating an approaching intersection): Black inscriptions on a YELLOW background with an arrow.

What are the three mandatory VFR/IFR airspeed limits established by 14 CFR 91.117?

1. Below 10,000 feet MSL: Maximum 250 KIAS (knots indicated airspeed); 2. Within 4 NM and at or below 2,500 feet AGL of the primary airport of a Class C or Class D airspace: Maximum 200 KIAS; 3. Underlying a Class B airspace shelf or in a VFR corridor through Class B airspace: Maximum 200 KIAS.

What are the ATC Light Gun Signals for an aircraft In Flight versus On the Ground for Steady Green, Flashing Green, and Steady Red?

Steady Green: Cleared to land (In Flight) / Cleared for takeoff (On Ground). Flashing Green: Return for landing, followed by steady green at proper time (In Flight) / Cleared to taxi (On Ground). Steady Red: Give way to other aircraft and continue circling (In Flight) / Stop (On Ground).

What are the standard vertical and lateral dimensions, charting depiction, and entry requirements for Class C airspace?

Class C typically consists of a 5 NM radius inner core from the surface to 4,000 feet AGL and a 10 NM radius outer shelf from 1,200 to 4,000 feet AGL, depicted by solid magenta lines. Entry requires an operable two-way radio, Mode C transponder + ADS-B Out, and establishing two-way radio communication prior to entry.

What are the typical dimensions, charting depiction, and ATC communication requirement to enter Class B airspace?

Class B surrounds the nation's busiest airports from the surface to 10,000 feet MSL in an 'upside-down wedding cake' configuration, depicted by solid blue lines on Sectional Charts. To enter, the pilot must receive an explicit ATC clearance stating 'Cleared into the Class B airspace'—merely establishing two-way radio contact is NOT sufficient.

What are the VFR visibility and cloud clearance minimums inside Class B airspace, and why is 'Clear of Clouds' permitted there?

3 statute miles (SM) flight visibility and Clear of Clouds. Because all aircraft inside Class B airspace (both IFR and VFR) are subject to positive ATC radar separation and explicit ATC clearances, the standard 500-below / 1,000-above / 2,000-horizontal cloud buffer is not required.

What are the four universal emergency and standard transponder squawk codes?

1200 — Standard VFR code (all altitudes when not assigned a discrete ATC code); 7500 — Hijacking / Unlawful Interference ('75 — taken alive'); 7600 — Lost Radio Communications / NORDO ('76 — need a radio fix'); 7700 — General In-Flight Emergency ('77 — going to heaven'). Pilots should never cycle through 7500/7600/7700 when changing codes.

What are the minimum ceiling and ground visibility required for basic VFR takeoff, landing, or traffic pattern entry within a controlled surface area (91.155)?

Unless operating under a Special VFR clearance, no person may operate an aircraft beneath the ceiling under VFR within the lateral boundaries of controlled airspace designated to the surface for an airport when the ceiling is less than 1,000 feet AGL, or take off/land unless ground visibility (or flight visibility if ground visibility is unreported) is at least 3 statute miles.

How are the different base altitudes of Class E airspace depicted on an FAA VFR Sectional Chart?

1. Dashed magenta line: Class E begins at the surface; 2. Shaded magenta vignette (feathered edge): Class E begins at 700 feet AGL (fading toward the 700 ft side); 3. Shaded blue vignette: Class E begins at 1,200 feet AGL adjacent to non-1,200 ft airspace; 4. No boundary shown: Class E begins at 1,200 feet AGL by default across most of the U.S. (and extends up to 17,999 ft MSL).

What is a Tri-Color VASI, and why is its amber transition zone potentially hazardous?

A Tri-Color VASI uses a single light unit projecting Amber above glidepath, Green on glidepath, and Red below glidepath. Between the Green (on-slope) and Red (low) beams, dark atmospheric refraction can produce a narrow false Amber band just below the green beam, potentially tricking a low pilot into believing they are too high and pitching down into terrain.

How are Runway Holding Position Markings painted on a taxiway, and which side must an aircraft stop on prior to ATC clearance?

They consist of four yellow lines across the taxiway: two solid yellow lines and two dashed yellow lines. An aircraft taxiing from the ramp toward the runway encounters the two SOLID lines first and must hold short completely behind the solid lines until explicitly cleared onto or across the runway. Exiting a runway crosses the dashed lines first.

What do the magenta flag symbol, solid magenta circle ('R'), and blue/magenta airport symbols with ticks vs. solid circles signify on a Sectional Chart?

A magenta flag marks an official VFR Waypoint/Reporting Point. An 'R' inside a circle near a VOR indicates a RCO (Remote Communications Outlet) where a Flight Service Station can be contacted. Airports are blue if they have an operating control tower and magenta if nontowered; outer tick marks indicate fuel/services are available, and circular symbols indicate non-hard-surface or short runways (<1,500 ft).

How do pilot light indications work on a standard 2-bar VASI (Visual Approach Slope Indicator) versus a 4-light PAPI (Precision Approach Path Indicator)?

On a 2-bar VASI: Red over White = on glidepath ('Red over White, you're all right'); White over White = above glidepath ('White over White, you're high as a kite'); Red over Red = below glidepath ('Red over Red, you're dead'). On a 4-light PAPI: 2 White (left) and 2 Red (right) = on standard 3° glidepath; 4 White = well above glidepath; 4 Red = well below glidepath.

National Airspace System (Classes A, B, C, D, E, G), VFR Weather Minimums & Sectional Charts

FAA National Airspace System classification, dimensions, pilot and equipment entry requirements, VFR visibility and cloud clearance minimums, Special VFR, speed limits, Special Use Airspace, airport signage/markings, visual glidepath indicators, and transponder squawk codes.

Level: basic
Languages: en → en
Cards: 32
Markdown: National Airspace System (Classes A, B, C, D, E, G), VFR Weather Minimums & Sectional Charts (.md)

Flashcards (32)

#	Front (Term / Question)	Back (Definition / Answer)
1	Compare Military Operations Areas (MOAs), Alert Areas, and Warning Areas on Sectional Charts.	MOAs separate military training activities from IFR traffic; VFR pilots may enter without clearance but should exercise extreme caution and contact the controlling agency. Alert Areas contain a high volume of pilot training or unusual aerial activity where all participating and transiting pilots share responsibility for collision avoidance. Warning Areas extend from 3 NM outward from the U.S. coast over international waters and contain hazards similar to Restricted Areas.
2	On an FAA VFR Sectional Chart, what does a star (*) above the airport beacon symbol indicate, and what indicates a right-hand traffic pattern?	A star beside the airport symbol indicates a rotating airport beacon operates from sunset to sunrise (an asterisk inside the airport data block indicates part-time or pilot-controlled beacon operation). 'RP' followed by runway numbers in the airport data block indicates a non-standard Right Traffic Pattern for those specific runways (standard pattern is left-hand turns).
3	What are the vertical limits, operating rules, and altimeter setting requirements for Class A airspace?	Class A airspace extends from 18,000 feet MSL up to and including FL600 over the 48 contiguous states and Alaska (within 12 NM of the coast). All operations must be conducted under Instrument Flight Rules (IFR) with an IFR clearance, an Instrument-rated pilot, and the altimeter set to standard pressure (29.92" Hg).
4	How are Runway Edge Lights, Taxiway Edge Lights, and Runway Threshold Lights color-coded at night?	Runway Edge Lights are white, except on instrument runways where the last 2,000 feet (or half the runway length, whichever is less) are yellow (amber) to form a caution zone. Taxiway Edge Lights are blue (Taxiway Centerline lights are green). Runway Threshold Lights are green facing approaching aircraft and red facing the departure end.
5	Compare the VFR visibility and cloud clearance minimums in Class E airspace below 10,000 feet MSL versus at or above 10,000 feet MSL.	Below 10,000 feet MSL: 3 SM visibility, 500 feet below, 1,000 feet above, and 2,000 feet horizontal from clouds (3-5-1-2). At or above 10,000 feet MSL (and more than 1,200 ft AGL): 5 SM visibility, 1,000 feet below, 1,000 feet above, and 1 statute mile horizontal from clouds (5-1-1-1) due to higher closure speeds of aircraft above the 250-knot speed limit.
6	What is a Controlled Firing Area (CFA), and how is it depicted on an aeronautical chart?	A CFA contains hazardous ordnance activities that are immediately suspended whenever spotter aircraft, radar, or ground lookout personnel detect an approaching aircraft. Because the activity ceases rather than requiring aircraft to deviate, CFAs are NOT depicted on aeronautical charts.
7	What are the VFR weather minimums in Class G airspace above 1,200 feet AGL, both below and above 10,000 feet MSL?	More than 1,200 feet AGL but less than 10,000 feet MSL: Day requires 1 SM visibility and 500 ft below, 1,000 ft above, 2,000 ft horizontal; Night requires 3 SM visibility and 500/1,000/2,000 ft. More than 1,200 feet AGL and at or above 10,000 feet MSL (Day or Night): 5 SM visibility and 1,000 ft below, 1,000 ft above, and 1 SM horizontal (5-1-1-1).
8	What are the VFR weather minimums in Class G (uncontrolled) airspace during the Day vs. Night at or below 1,200 feet AGL?	Day at or below 1,200 feet AGL: 1 SM flight visibility and Clear of Clouds. Night at or below 1,200 feet AGL: 3 SM flight visibility and 500 feet below, 1,000 feet above, and 2,000 feet horizontal from clouds (3-5-1-2). Exception: In an airport traffic pattern at night within 1/2 mile of the runway, 1 SM and Clear of Clouds is permitted if remaining below 1,200 ft AGL.
9	Distinguish between a Displaced Threshold and a Relocated Threshold (Blast Pad / Stopway with yellow chevrons).	A Displaced Threshold (marked by white arrows leading up to a white threshold bar) may be used for taxiing, takeoff roll, and rollout after landing from the opposite direction, but NOT for landing touchdown. A Blast Pad / Stopway (marked by large yellow chevrons) is not usable for any normal ground operations (no taxi, takeoff, or landing), except for emergency rollout stopping.
10	For Class C and Class D airspace entry, what ATC response constitutes 'establishing two-way radio communications' versus being prohibited from entering?	Two-way radio communication is established if the controller responds to the initial radio call using the aircraft's specific callsign (even if the controller says '[Aircraft Callsign], standby'). If the controller responds only with 'Aircraft calling [Approach/Tower], standby' without stating the callsign, the pilot may NOT enter the airspace.
11	How is Maximum Elevation Figure (MEF) calculated on a Sectional Chart quadrant, and how is it depicted?	The MEF is shown in thousands and hundreds of feet (e.g., 12^5 = 12,500 feet MSL) within each 30-minute latitude by 30-minute longitude quadrangle. It is calculated by taking the highest known terrain or man-made obstacle in the quadrant, adding 100 feet for vertical error (plus 200 feet for uncharted obstacles if based on terrain), and rounding up to the next higher 100-foot level.
12	What is a Runway Incursion, and what is marked by a dashed circle/ellipse labeled 'HS 1' on an FAA Airport Diagram?	A Runway Incursion is any occurrence at an aerodrome involving the incorrect presence of an aircraft, vehicle, or person on the protected area of a surface designated for the landing and takeoff of aircraft. 'HS 1' marks a Runway Safety 'Hot Spot'—a complex or confusing taxiway/runway intersection with a history of surface incidents requiring heightened pilot situational awareness.
13	What are the standard dimensions, charting depiction, and VFR weather minimums for Class D airspace?	Class D extends from the surface to 2,500 feet AGL (converted to MSL and shown in a dashed blue box, e.g., [25] for 2,500 ft MSL) around airports with an operating control tower, depicted by a dashed blue line. VFR minimums are 3 SM flight visibility and 500 feet below, 1,000 feet above, and 2,000 feet horizontal from clouds ('3-5-1-2').
14	Distinguish between Prohibited Areas and Restricted Areas in Special Use Airspace.	Prohibited Areas (e.g., P-40 Camp David, P-56 White House) forbid flight by all aircraft at all times for national security reasons. Restricted Areas (e.g., R-2508) contain unusual, often invisible hazards to aircraft (such as artillery firing, aerial gunnery, or guided missiles); VFR flight is permitted only during inactive hours or with explicit authorization from the controlling agency.
15	What are the ATC Light Gun Signals for an aircraft In Flight versus On the Ground for Flashing Red, Flashing White, and Alternating Red and Green?	Flashing Red: Airport unsafe, do NOT land (In Flight) / Taxi clear of the runway in use (On Ground). Flashing White: Not applicable in flight / Return to starting point on airport (On Ground). Alternating Red and Green: Exercise extreme caution (both In Flight and On the Ground).
16	What are the requirements to fly through an Air Defense Identification Zone (ADIZ) under VFR?	An operational two-way radio, an operating altitude-encoding transponder (Mode C/S) on a discrete ATC-assigned squawk code, and an active Defense VFR (DVFR) flight plan filed prior to penetration with an estimated time and point of ADIZ penetration (which must be adhered to within +/- 5 minutes and 10–20 NM).
17	What are the weather minimums and pilot/aircraft requirements for a Special VFR (SVFR) clearance in a controlled surface area?	Weather minimums: At least 1 SM flight visibility and Clear of Clouds (helicopters have no minimum visibility requirement). Pilot must specifically request SVFR (ATC cannot offer it). For SVFR operations between sunset and sunrise (Night), the pilot MUST hold an Instrument Rating and the aircraft MUST be equipped for IFR flight under 14 CFR 91.205(d).
18	What is the Mode C / ADS-B Out Veil surrounding a Class B primary airport?	An airspace cylinder extending 30 nautical miles (NM) from the primary Class B airport from the surface up to 10,000 feet MSL (depicted by a thin solid magenta circle on Sectional Charts). Within this veil, all aircraft must be equipped with an operable Mode C or Mode S altitude-encoding transponder and 14 CFR 91.225 ADS-B Out (unless flying an aircraft originally certificated without an engine-driven electrical system).
19	When an airport's Class D or Class C control tower closes for the night, what does the surface airspace revert to?	It typically reverts to either Class E surface area (if continuous weather reporting and instrument approaches remain active) or Class G uncontrolled airspace, as specified in the Chart Supplement U.S. (formerly A/FD).
20	How do airport Runway Holding Position Signs, Taxiway Location Signs, and Taxiway Direction Signs differ in color scheme?	1. Mandatory Instruction / Runway Holding Position Signs: White inscriptions on a RED background; 2. Taxiway Location Signs (indicating the taxiway or runway you are currently on): Yellow inscriptions on a BLACK background with a yellow border; 3. Taxiway Direction Signs (indicating an approaching intersection): Black inscriptions on a YELLOW background with an arrow.
21	What are the three mandatory VFR/IFR airspeed limits established by 14 CFR 91.117?	1. Below 10,000 feet MSL: Maximum 250 KIAS (knots indicated airspeed); 2. Within 4 NM and at or below 2,500 feet AGL of the primary airport of a Class C or Class D airspace: Maximum 200 KIAS; 3. Underlying a Class B airspace shelf or in a VFR corridor through Class B airspace: Maximum 200 KIAS.
22	What are the ATC Light Gun Signals for an aircraft In Flight versus On the Ground for Steady Green, Flashing Green, and Steady Red?	Steady Green: Cleared to land (In Flight) / Cleared for takeoff (On Ground). Flashing Green: Return for landing, followed by steady green at proper time (In Flight) / Cleared to taxi (On Ground). Steady Red: Give way to other aircraft and continue circling (In Flight) / Stop (On Ground).
23	What are the standard vertical and lateral dimensions, charting depiction, and entry requirements for Class C airspace?	Class C typically consists of a 5 NM radius inner core from the surface to 4,000 feet AGL and a 10 NM radius outer shelf from 1,200 to 4,000 feet AGL, depicted by solid magenta lines. Entry requires an operable two-way radio, Mode C transponder + ADS-B Out, and establishing two-way radio communication prior to entry.
24	What are the typical dimensions, charting depiction, and ATC communication requirement to enter Class B airspace?	Class B surrounds the nation's busiest airports from the surface to 10,000 feet MSL in an 'upside-down wedding cake' configuration, depicted by solid blue lines on Sectional Charts. To enter, the pilot must receive an explicit ATC clearance stating 'Cleared into the Class B airspace'—merely establishing two-way radio contact is NOT sufficient.
25	What are the VFR visibility and cloud clearance minimums inside Class B airspace, and why is 'Clear of Clouds' permitted there?	3 statute miles (SM) flight visibility and Clear of Clouds. Because all aircraft inside Class B airspace (both IFR and VFR) are subject to positive ATC radar separation and explicit ATC clearances, the standard 500-below / 1,000-above / 2,000-horizontal cloud buffer is not required.
26	What are the four universal emergency and standard transponder squawk codes?	1200 — Standard VFR code (all altitudes when not assigned a discrete ATC code); 7500 — Hijacking / Unlawful Interference ('75 — taken alive'); 7600 — Lost Radio Communications / NORDO ('76 — need a radio fix'); 7700 — General In-Flight Emergency ('77 — going to heaven'). Pilots should never cycle through 7500/7600/7700 when changing codes.
27	What are the minimum ceiling and ground visibility required for basic VFR takeoff, landing, or traffic pattern entry within a controlled surface area (91.155)?	Unless operating under a Special VFR clearance, no person may operate an aircraft beneath the ceiling under VFR within the lateral boundaries of controlled airspace designated to the surface for an airport when the ceiling is less than 1,000 feet AGL, or take off/land unless ground visibility (or flight visibility if ground visibility is unreported) is at least 3 statute miles.
28	How are the different base altitudes of Class E airspace depicted on an FAA VFR Sectional Chart?	1. Dashed magenta line: Class E begins at the surface; 2. Shaded magenta vignette (feathered edge): Class E begins at 700 feet AGL (fading toward the 700 ft side); 3. Shaded blue vignette: Class E begins at 1,200 feet AGL adjacent to non-1,200 ft airspace; 4. No boundary shown: Class E begins at 1,200 feet AGL by default across most of the U.S. (and extends up to 17,999 ft MSL).
29	What is a Tri-Color VASI, and why is its amber transition zone potentially hazardous?	A Tri-Color VASI uses a single light unit projecting Amber above glidepath, Green on glidepath, and Red below glidepath. Between the Green (on-slope) and Red (low) beams, dark atmospheric refraction can produce a narrow false Amber band just below the green beam, potentially tricking a low pilot into believing they are too high and pitching down into terrain.
30	How are Runway Holding Position Markings painted on a taxiway, and which side must an aircraft stop on prior to ATC clearance?	They consist of four yellow lines across the taxiway: two solid yellow lines and two dashed yellow lines. An aircraft taxiing from the ramp toward the runway encounters the two SOLID lines first and must hold short completely behind the solid lines until explicitly cleared onto or across the runway. Exiting a runway crosses the dashed lines first.
31	What do the magenta flag symbol, solid magenta circle ('R'), and blue/magenta airport symbols with ticks vs. solid circles signify on a Sectional Chart?	A magenta flag marks an official VFR Waypoint/Reporting Point. An 'R' inside a circle near a VOR indicates a RCO (Remote Communications Outlet) where a Flight Service Station can be contacted. Airports are blue if they have an operating control tower and magenta if nontowered; outer tick marks indicate fuel/services are available, and circular symbols indicate non-hard-surface or short runways (<1,500 ft).
32	How do pilot light indications work on a standard 2-bar VASI (Visual Approach Slope Indicator) versus a 4-light PAPI (Precision Approach Path Indicator)?	On a 2-bar VASI: Red over White = on glidepath ('Red over White, you're all right'); White over White = above glidepath ('White over White, you're high as a kite'); Red over Red = below glidepath ('Red over Red, you're dead'). On a 4-light PAPI: 2 White (left) and 2 Red (right) = on standard 3° glidepath; 4 White = well above glidepath; 4 Red = well below glidepath.