Reading the Sectional Chart

A sectional chart is the legal map of low-altitude flying: where the airspace boundaries sit, where the airports are, what sticks up out of the ground, and where manned traffic concentrates. Learn to read it and "can I fly here?" becomes a question you answer in seconds. The exam hands you excerpts from the Airman Knowledge Testing Supplement (FAA-CT-8080-2H) and expects you to read them. Roughly a fifth of the exam touches this skill. The chart legend is printed in the front of the supplement and you may use it during the test - but you won't have time to look everything up, so learn the symbols.

Scale: 1:500,000. One inch is about 6.9 nautical miles.

Airports: color and shape

• Blue airport symbol = the airport has a control tower. Magenta = no tower.
• Blue does NOT mean Class B airspace. The color of the airport symbol is about the tower, not the airspace class. A blue (towered) airport can sit inside Class C or D. This trap is staged on the exam.
• Runway-shaped outline as the airport icon = the airport has a runway longer than 8,069 ft. Circle with runway marks inside = runways between 1,500 and 8,069 ft. Plain circle (no runway marks) = soft-surface strips (grass, gravel, dirt). You will essentially never see a blue plain circle - towered airports have paved runways.
• Star on top of the symbol = rotating beacon, operating sunset to sunrise.
• Tick marks around the symbol = fuel services available and the field is attended during normal working hours. What kind of fuel is in the Chart Supplement, not on the chart.
• Small open dot on the field = a VOR navigation station is on the airport. A big tick-marked circle around it is the VOR compass rose, which reads in magnetic degrees.
• H in a circle = heliport. Anchor = seaplane base. X on the field = closed/abandoned airport (still charted so pilots know it's closed; landing there without a real emergency is a §91.13 careless-operation problem).
• R in a magenta circle = restricted (private) airport - permission required. Absence of the R does not make a private strip public.
• U in a circle = unverified airport (FAA can't confirm current status).
• Magenta flag = VFR checkpoint. This is the answer to "why does a remote pilot care about this flag": manned traffic concentrates there, because pilots and ATC use it as a visual reporting point.

The airport data block

The text next to the airport symbol, top to bottom. Example, DFW-style:

NO SVFR
DALLAS-FT WORTH INTL (DFW)
CT - 124.15 *  © 122.95
ATIS 123.775
606  L 134  122.95
RP 12R, 30R

• NO SVFR - Special VFR clearances not allowed (busy Class B/C fields). Standard VFR needs 3 SM visibility; a Special VFR clearance lets manned aircraft in with as little as 1 SM. Not for drones; just recognize it.
• (DFW) - location identifier.
• CT - 124.15 - control tower frequency, always in MHz (the exam offers wrong-unit distractors). Big airports list several.
• *star () after CT - the tower is part-time**. Hours live in the Chart Supplement. When the tower is closed the airspace typically reverts to Class E or G and pilots self-announce.
• © (C in circle) - CTAF, the Common Traffic Advisory Frequency pilots use to self-announce when there's no (or a closed) tower. At part-time-tower fields the CTAF is usually the tower frequency. The exam will ask you to find a CTAF.
• ATIS 123.775 - continuous recorded broadcast of airport info (weather, runway in use). When the exam asks "what frequency for weather at this airport," the answer is the ATIS/AWOS/ASOS frequency - the tower frequency is the distractor.
• 606 - field elevation in feet MSL. Always the leftmost figure on the bottom line.
• L - runway lighting. *L = lighting with limitations (often pilot-activated: keying the mic clicks the lights on).
• 134 - length of the longest runway in hundreds of feet: add two zeros → 13,400 ft.
• 122.95 - UNICOM (pilot-to-pilot advisory frequency, not ATC). Usually 122.7/122.8/122.95-family numbers.
• RP 12R, 30R - right traffic pattern for those runways only. The default pattern is LEFT-hand; runways not listed after RP are left-pattern. At the biggest airports (LAX, JFK, Dulles) runway numbers and RP notes are deliberately absent from the chart - ATC directs everything there.

Airspace lines (the part that decides whether you need authorization)

• Solid blue line = Class B. Solid magenta = Class C.
• Dashed blue = Class D. Dashed magenta = Class E down to the surface.
• Faded/shaded magenta vignette = Class E starts at 700 ft AGL inside the band. Outside it (and with no marking at all) Class E starts at 1,200 ft AGL; below that floor is Class G.
• Faded blue vignette (rare, mostly western US) = Class E floor at 1,200 AGL drawn explicitly.
• Blue "zipper" line = Class E begins at the specific MSL altitude printed next to it (e.g. 3400 MSL). Below it, Class G runs up to that MSL figure - the one case where a Class G ceiling is MSL-referenced.
• Altitude "fractions" on B/C shelves: ceiling over floor, in hundreds of feet - add two zeros. 42/21 = 4,200 MSL ceiling, 2,100 MSL floor. SFC as the bottom number = the shelf starts at the surface.
• Any number in a box is MSL. Always. Class D ceilings print in a dashed box: [26] = 2,600 MSL.
• A minus sign in the box means "up to but not including." [-20] = Class D from the surface to 1,999 MSL. The minus exists because a Class B or C shelf sits directly on top at 2,000. [32] with no minus = ceiling exactly 3,200 MSL, nothing pressing down on it.
• Class C is layered like a two-tier wedding cake: typical inner core surface-to-4,000 MSL, outer shelf floor ~1,300–2,100 MSL. Class B is the full upside-down wedding cake with 3+ shelves. Real charts use real numbers (Atlantic City: SFC–4,100 and 1,300–4,100) - read them, don't assume.
• Look for hidden airspace: dashed-blue Class D circles tucked inside magenta Class C shelves are easy to miss at supplement print size.
• Mode C veil: the thin ring labeled MODE C, 30 NM around Class B core airports - inside it, aircraft need altitude-reporting transponders. Know what the ring is; it isn't a drone authorization boundary.

Special-use airspace

• R-#### with blue perpendicular hash marks = Restricted area (live fire, missile tests, etc.). If it's "hot" you stay out without permission from the controlling agency; if "cold" you may transit - check NOTAMs or ask ATC.
• W-## = Warning area: starts beyond 3 NM offshore, over international waters - advisory, not FAA-controlled, but the hazards are just as real.
• MOA (magenta hash marks) = Military Operations Area. You may fly there without authorization (if the underlying class permits), but treat it as hot and check NOTAMs. Hash-mark orientation is the tell: perpendicular = restricted; slanted = MOA.
• VR/IR + number = Military Training Route (fast, low military traffic). Four digits = the whole route is at or below 1,500 ft AGL (i.e., in your world). Three digits or fewer = it has segments above 1,500.
• Victor airways: faded blue lines VOR-to-VOR, labeled V12, V289... - highways in the sky, 8 NM wide (4 each side), always Class E from 1,200 AGL to 17,999 MSL. To you they mean: concentrated manned traffic along that line.
• Isogonic line: dashed magenta straight line labeled e.g. 9°W - magnetic variation between true and magnetic north.
• TAC boundary: white band labeled TAC = the edge of a more-detailed Terminal Area Chart. It's a chart, not a frequency - the exam offers "something you tune to" as a distractor.

Obstacles

• Top number = height of the top in MSL. Parenthesized number = AGL. 2549 (1731) - and note MSL − AGL = ground elevation (818 here). Anchor the ground elevation once and you can convert between references freely.
• Tall skinny icon = obstacle 1,000 ft AGL or taller. Short icon = under 1,000 AGL. M-shaped double peak = multiple obstacles clustered.
• Lightning bolts at the tip = high-intensity lighting. UC = under construction - height not verified, be suspicious.
• Guy wires: the 2,000-ft standoff from tower guy wires is guidance, not regulation - but the wires are nearly invisible, which is the actual danger.

MEF - the big blue quadrant numbers

Each 30-minute × 30-minute lat/long quadrant carries a Maximum Elevation Figure: big digit = thousands, small digit = hundreds. Big 2 small 6 = 2,600.

• It is the height of the highest obstacle or terrain in the quadrant, in MSL (MSL because it's constant; AGL varies with the ground).
• It is a safety reference, not a law - the exam likes to imply it's a legal minimum. It isn't.
• How it's built (and how they'll make you compute it):
• Highest obstacle is man-made: obstacle MSL + 100 ft, round UP to the next hundred. 2,477 → 2,577 → 2,600.
• Highest feature is natural terrain: + 100 ft possible vertical error + 200 ft for possible unlit natural growth, round UP. 6,850 → 7,150 → 7,200.

Latitude and longitude

• Latitude = horizontal lines ("latitude means lateral"), degrees north/south of the equator (0°). Longitude = vertical meridians, degrees east/west of the prime meridian at Greenwich. Latitude is always stated first.
• One degree = 60 minutes. On the chart, small ticks are 1 minute, bigger ticks 5 and 10 minutes, and the full line halfway between degree lines is the 30-minute line - count from it instead of from the degree line when the target is nearer to it.
• Get to the neighborhood first: find the whole-degree intersection, then count minutes. Counting west means counting in the west direction - direction of count is where people go wrong.
• Formats: 36°24'N (degrees-minutes), with seconds (47°34'30"N), or decimal (46.9°N). Decimal → minutes: multiply the fraction by 60 (0.9 × 60 = 54').
• Exam-phrasing to recognize: lat/long lines "cross the equator at right angles."

The one skill that ties it together: max legal altitude

The classic hard question: "You're inspecting towers at [location]. Flying the maximum allowable altitude, what airspace are you in?" The procedure:

1. Find the tallest tower in the group. Read its AGL height.
2. Max altitude = tower AGL + 400 ft, only within a 400-ft radius of the structure (§107.51's 400-over-structure allowance).
3. Compare against the airspace floors above you. The 400-over-structure rule does NOT let you enter lateral B/C/D or surface-Class-E without authorization. But it CAN legally carry you up through an overlying 700/1,200-AGL Class E floor when you're operating from Class G.
4. Convert AGL ↔ MSL by adding/subtracting ground elevation when the shelf floors are MSL. Never bolt 400 onto an MSL number without thinking about what reference you're in.

Worked example (supplement Figure 25, Area 8): towers SW of Dallas Executive, tallest 2,549 MSL / 1,731 AGL. Max altitude 1,731 + 400 = 2,131 AGL = 2,949 MSL. Class E starts at 1,200 AGL there, Class B floor above is 3,000 MSL. Answer: you're in Class E, 51 ft under the B shelf - legal, no authorization needed at or above 400 AGL? No: legal because Class E at altitude is not one of §107.41's restricted volumes. That distinction - E-at-altitude vs E-designated-to-the-surface - is the sharpest trap in the whole area.

Traps to drill

• Blue airport ≠ Class B.
• Boxed minus = up to but not including.
• Weather frequency = ATIS/AWOS/ASOS, never the tower.
• Frequencies are MHz.
• MSL vs AGL: which one did the question ask for? Both appear as choices.
• MEF is not a legal altitude.
• 400-over-structure does not defeat §107.41 airspace authorization.
• TAC is a chart, not a broadcast.