Private Pilot · Unit 6 · 30 min

Reading the Sectional Chart

Lesson goals

By the end of this lesson you will know:

what a sectional chart shows, at what scale it is drawn, and how often a new edition takes effect
what the color, shape, tick marks, and star of an airport symbol each tell you about the airport
how to read every field of an airport data block, including the part-time tower star, the circled C, and the RP notation
what the maximum elevation figure in a quadrangle covers, and the arithmetic that produces it
which of an obstruction's two printed figures is measured from sea level and which from the ground
where the airport diagram and its hot spot circles are published, and what one hot spot circle marks

What a sectional chart is

A sectional aeronautical chart, called a sectional, is the chart you plan and fly a VFR cross-country on. It is drawn at a scale of 1:500,000, at which one inch on the sheet is 6.86 nautical miles. The AIM describes the series as designed for visual navigation of slow to medium speed aircraft (AIM 9-1-5). Each sectional is named after a major city within the area it covers (FAA Aeronautical Chart Users' Guide).

Three kinds of information share the one sheet. The topographic information consists of contour lines, shaded relief, drainage patterns, and an extensive selection of visual checkpoints and landmarks used for flight under VFR. The cultural features include cities and towns, roads, railroads, and other distinct landmarks. The aeronautical information includes visual and radio aids to navigation, airports, controlled airspace, special use airspace, obstructions, and related data (AIM 9-1-5). The legend panel printed on the sheet decodes nearly all of it, and it also carries air traffic control frequencies and information on airspace (PHAK Chapter 16).

A wide sectional chart excerpt covering the Los Angeles basin and the coastline. Airport symbols in blue and in magenta are scattered across the frame, each with a block of text beside it giving a name, an identifier, frequencies, and numbers. Heavy solid blue lines with stacked pairs of numbers divide the area into airspace tiers, and several dashed blue circles enclose individual airports. Built-up areas print as a solid yellow tint, water as pale blue, and higher ground at the top left as tan and brown bands crossed by fine contour lines. Boxed notes in magenta and blue carry frequencies and instructions, and small inverted-V symbols with numbers beside them mark obstructions. — One sheet carries airports and their frequencies, the airspace boundaries, the shape of the ground, obstructions, and the towns and roads you navigate by. Los Angeles Sectional Aeronautical Chart, effective 9 July 2026 (FAA), cropped.

A new edition of each sectional takes effect every 56 days (AIM 9-1-5). The effective dates are printed on the chart itself, and the next scheduled edition date is printed on the cover. The changeover time is 0901Z, chosen because air traffic volume is historically lower then, so that every pilot and controller is working from the same edition at the same moment. Aeronautical information changes faster than the cycle does, so the Users' Guide directs pilots to always use current editions, to discard obsolete charts and publications, and to check NOTAMs for the changes that fall between cycles. 14 CFR 91.103 requires each pilot in command, before beginning a flight, to become familiar with all available information concerning that flight.

The same symbols appear at twice the size on a VFR terminal area chart (TAC), which is drawn at 1:250,000, or one inch to 3.43 nautical miles. A TAC depicts the airspace designated as Class B airspace, and it should be used by pilots intending to operate to or from airfields within or near Class B or Class C airspace (AIM 9-1-5). Where a TAC exists, its coverage is outlined on the sectional by a masked line with a note beside it.

AIM 9-1-5; FAA Aeronautical Chart Users' Guide, "Explanation of VFR Terms and Symbols," "Keep Your Charts Current," and "Terminal Area Chart (TAC) Coverage"; PHAK Ch 16, "Aeronautical Charts"; 14 CFR 91.103

The airport symbol

The way an airport is printed on a sectional chart conveys four independent pieces of information.

A sectional chart excerpt showing two airports about six miles apart over a yellow city tint. On the left, San Bernardino International is drawn as the outline of its single long runway rather than as a circle, with a five-pointed star beside it, and its name, identifier, frequencies, and numbers printed above in dark green type, among them 1159 followed by an asterisk and the letter L. On the right, Redlands Municipal is drawn as a filled circle carrying a short runway line, with four short tick marks projecting from the circle at the diagonals and a five-pointed star above it, and its name, identifier, and numbers printed alongside in dark red type, reading 1574, then an asterisk and the letter L, then 45, then 123.05 with a circled C printed after it. A dashed boundary encloses the left airport, and a boxed number 32 sits beside it. Brown contour lines and spot elevations cover the higher ground at the top right. — San Bernardino International on the left and Redlands Municipal on the right. San Bernardino has a control tower, so its symbol and its data print in blue. Redlands has none, so its symbol and data print in magenta. The yellow city tint shifts both colors, so blue features print green and magenta features print dark red wherever they lie over it. Both airports carry a beacon star, and Redlands carries fuel tick marks. The dashed boundary and the boxed 32 are the Class D airspace covered in the airspace lesson. Los Angeles Sectional Aeronautical Chart, effective 9 July 2026 (FAA), cropped.

Tower status: The color in which the airport is charted indicates whether it has a control tower. Airports with control towers, and all of their related data, are shown in blue. All other airports and their related data are shown in magenta.

Runway types: Public-use landplane airports are drawn in one of three ways, and the surface and the length of the runways determine which of the three the chart uses. Where the hard-surfaced runways are greater than 8,069 feet, and at some airports with multiple runways shorter than that, the runway pattern itself is drawn in place of a circle. That is why San Bernardino above appears as a long diagonal strip. Where the hard-surfaced runways are 1,500 to 8,069 feet, the airport is drawn as a filled circle carrying a short runway line. Where the runways are other than hard-surfaced, the airport is drawn as an open circle. A seaplane base is drawn as an anchor.

Fuel availability: Tick marks around the basic airport symbol indicate that fuel is available at the airport, and the Users' Guide sends you to the Chart Supplement for the details and the availability. The chart does not tell you which grades, or when the pumps are open.

Airport beacon: A five-pointed star beside the symbol indicates the existence of a rotating or flashing airport beacon operating from dusk to dawn. The lighting lesson covered what that beacon looks like from the air and what its color pairs mean.

FAA Aeronautical Chart Users' Guide, "VFR Terms and Symbols: Airports"

The airport data block

Beside each airport symbol sits an airport data block, a compressed stack of two to four lines. The legend defines every character in it, and the order of the fields is fixed.

A sectional chart excerpt centered on Chino Airport, drawn as a filled dark blue circle carrying two crossing white runway lines with tick marks projecting from its rim, and a five-pointed star above and left of it. Four lines of dark green type sit below: CHINO in capitals followed by CNO in parentheses; then CT dash 118.5 followed by a star, a circled C, and ATIS 125.85; then 650, L 70, and 122.95; then RP 3, 8L, 8R. A dashed boundary curves around the airport with a boxed 27 beside it, a navigation aid box at the top right reads 112.2 Ch 59 PDZ above a second box reading RIVERSIDE, and an airway labelled V 197 crosses the top of the frame. — The Chino data block, four lines deep. The first line is the airport name and its location identifier. The second carries the control tower frequency, the star that marks part-time operation, the circled C that follows the common traffic advisory frequency, and the ATIS frequency. The third carries the field elevation, the lighting code, the longest runway in hundreds of feet, and the aeronautical advisory station. The fourth lists the runways flown with a right-hand pattern. Los Angeles Sectional Aeronautical Chart, effective 9 July 2026 (FAA), cropped.

Reading Chino line by line gives every field you will meet:

CHINO (CNO). Airports are identified by their official FAA designated name, followed by the location identifier in parentheses. Where an ICAO location identifier also applies, it prints in a second pair of parentheses.
CT - 118.5. CT introduces the control tower's primary frequency. This field appears only in blue, because only a towered airport has one.
The star after 118.5. A star in this position indicates that the tower operates part-time. The hours are in the tower frequencies tabulation printed on the chart. Chino's tower runs 1500 to 0500Z, so for part of every day this is a nontowered airport.
The circled C. The circled C follows the common traffic advisory frequency (CTAF), which is the frequency designated for airport advisory practices while operating to or from an airport without an operating control tower. It sits immediately after 118.5 here, so Chino's CTAF is the tower frequency. On the Redlands block in the previous section the circled C sits after 123.05 instead, because there the CTAF is the aeronautical advisory station frequency. The radio lesson covered what you say on it.
ATIS 125.85. The automatic terminal information service frequency. Where an airport has no full-time ATIS, an ASOS or AWOS frequency prints in this position instead, as the same lesson described.
650. The elevation in feet above mean sea level, which is the highest point on the usable portion of the landing areas.
L. The lighting code. A plain L means runway lights are on from dusk to dawn. An asterisk in front of it, printed as *L, means lighting limitations exist and you must consult the Chart Supplement to find them: lighting available on request, part-time lighting, or pilot-controlled lighting. Both airports in the previous section print *L. Lighting codes refer to runway edge lights. The lighted runway may not be the longest runway available, and the lights may not run its full length. A dash in this position means no runway edge lights.
70. The length of the longest runway in hundreds of feet, so 7,000 feet at Chino. The figure is the longest active runway, including displaced thresholds and excluding overruns, and the usable length may be less than it. It is rounded to the nearest 100 feet using 70 as the rounding point, so a runway 8,070 feet long is charted as 81 while one 8,069 feet long is charted as 80.
122.95. The aeronautical advisory station, which is the UNICOM frequency.
RP 3, 8L, 8R. Right traffic patterns are indicated at public-use and joint-use airports with the abbreviation RP for right pattern, followed by the appropriate runway numbers, at the bottom of the airport data block (AIM 4-3-3). Chino flies a right-hand pattern on runways 3, 8L, and 8R. An asterisk in front, printed as *RP, indicates special conditions or restrictions and sends you to the Chart Supplement. Right traffic patterns are not shown at airports with full-time control towers (AIM 4-3-3). Chino's tower is part-time, which is why its block carries the line. Do not read a missing RP line at a full-time towered field as a promise of left traffic. The traffic pattern lesson covered what the direction of turns requires of you.

Where information is lacking for a field, the respective character is replaced by a dash. Two more marks attach to the airport name rather than to the block. NO SVFR printed above the name marks an airport where fixed-wing special VFR operations are prohibited. The weather minimums lesson covered the clearance those operations require. An airport name printed inside a solid line box marks a part 93 special air traffic rule and airport traffic pattern, and sends you to the Chart Supplement for the requirements.

FAA Aeronautical Chart Users' Guide, "VFR Terms and Symbols: Airports"; AIM 4-3-3

Terrain and the maximum elevation figure

The FAA uses five techniques together to show the shape and height of the ground: contour lines, shaded relief, color tints, obstruction symbols, and maximum elevation figures.

A sectional chart excerpt of a mountain range, printed in tan and brown bands with pale green in the valleys. Fine brown contour lines wind across the whole frame, closely packed on the steep slopes and labelled 7000 in two places. A large blue numeral 104 stands at the left, its final digit printed smaller and raised. Black numerals beside heavy black dots read 10064 at the right and 5826 and 5796 in the middle. At the top left a black circle containing a solid triangle marks a lookout tower, with its base elevation 7783 beside it. Near the bottom edge an obstruction symbol prints 5558 with 220 in parentheses below it. Green dotted boundaries enclose an area labelled Sheep Mountain Wilderness Area, a magenta airport named USFS prints its elevation 2700 with the note Emerg Only, and a magenta circled H marks a heliport. — The San Gabriel Mountains. The tint bands and the contour lines give the shape of the ground, the black numerals beside heavy dots are spot elevations in feet above sea level, and the large blue 104 is the maximum elevation figure for the quadrangle. Its final digit is printed smaller because the last two digits of the figure are not shown: 104 is 10,400 feet. The FAA computes the figure from the 10,064 foot spot elevation at the right, which is the highest terrain in the quadrangle. Los Angeles Sectional Aeronautical Chart, effective 9 July 2026 (FAA), cropped.

A contour line joins points of equal elevation. On sectionals, basic contours are spaced at 500 foot intervals. Intermediate contours are typically at 250 foot intervals in moderately level or gently rolling areas, and auxiliary contours at 50, 100, 125, or 150 foot intervals occasionally show smaller relief features where the relief is low. Widely spaced contours represent gentle slopes, and closely spaced contours represent steep slopes. Shaded relief is drawn as if the light were coming from the northwest, because human visual perception has been conditioned to that view. Color tints show bands of elevation relative to sea level, ranging from light green for the lower elevations to dark brown for the higher ones. A heavy dot with a number beside it is a spot elevation, giving the elevation of that point in feet above sea level.

The large blue number in each quadrangle is the maximum elevation figure (MEF), and it represents the highest elevation within a quadrant, including terrain and other vertical obstacles such as towers and trees. A quadrant on sectionals is the area bounded by the ticked lines dividing each 30 minutes of latitude and each 30 minutes of longitude. MEF figures are rounded up to the nearest 100 foot value, and the last two digits of the number are not shown, which is why the last digit prints smaller and raised. The 104 in the figure above is 10,400 feet above sea level.

The figure is not simply the highest elevation rounded up. Where a natural terrain feature is the highest feature in the quadrangle, the FAA determines the elevation of the feature, adds the possible vertical error of the source, adds a 200 foot allowance for uncharted natural or man-made obstacles, and then rounds up to the next higher hundred-foot level. The source error added is 100 feet, or half the contour interval where the interval on the source exceeds 200 feet. The 200 foot allowance exists because chart specifications do not require obstacles below a minimum height to be portrayed at all. Working that through for the figure above: the highest terrain in the quadrangle is 10,064 feet, plus 100 feet of possible vertical error is 10,164, plus the 200 foot obstacle allowance is 10,364, and rounding up to the next hundred gives 10,400. The chart prints 104.

Where instead a man-made obstacle stands more than 200 feet above the highest terrain in the quadrant, the FAA takes the elevation of the top of the obstacle above sea level, adds the same possible vertical error, and rounds up. That procedure adds no 200 foot allowance.

An MEF is not a minimum altitude The MEF states the highest elevation the FAA computed for one 30-minute quadrangle. It is not a clearance altitude, and it carries no margin for your airplane. The Users' Guide warns that while the figures are based on the best information available to the specialist, they are not verified by field surveys. Terrain and obstruction clearance planning is your own arithmetic on top of the figure.

FAA Aeronautical Chart Users' Guide, "Land Features (Terrain) and Obstructions" and "VFR Symbology: Relief"

Obstructions

Sectionals and TACs typically show man-made obstacles extending more than 200 feet above ground level, or more than 299 feet above ground level inside the yellow city tint. Smokestacks, tanks, factories, lookout towers, antennas, and wind turbines are among the features treated as hazardous obstacles to low-level flight.

A sectional chart excerpt of a mountain ridge in tan and pale green with fine brown contour lines. Near the center stands a blue symbol shaped like two joined peaks with three dots at its base and two dots above it. Printed above the symbol in blue is 6634, and directly below that, in parentheses, 971. A small black square to the right is labelled Mt. Wilson Observatory in black type. A magenta hexagon containing the letter H sits above and right of the obstruction symbol. At the left edge the words CLASS C print in blue beside a large blue 75, and at the bottom of the frame a black landmark square is labelled ROSE BOWL and an airport name reads SAN GABRIEL VALLEY, with EMT in parentheses. — The antenna farm on Mount Wilson. The joined double peak with dots at its base is the group obstruction symbol, used where obstacles stand close together. The upper figure, 6,634, is the elevation of the top above sea level. The parenthesized figure, 971, is the height of the structure above the ground. No lighting symbol is drawn around this obstruction. The blue CLASS C and the 75 belong to the airspace covered in the airspace lesson. Los Angeles Sectional Aeronautical Chart, effective 9 July 2026 (FAA), cropped.

The chart draws an obstruction at one of two symbol heights, and the taller symbol carries a bar near its top. The short symbol marks an obstacle above 200 feet and below 1,000 feet above ground level, or above 299 feet in an urban area. The tall symbol marks an obstacle 1,000 feet above ground level or greater.

Two figures print with the symbol, and the order is fixed. The elevation of the top of the obstacle above mean sea level comes first, and the height of the structure above ground level follows in parentheses below it. Mount Wilson above is therefore a structure 971 feet tall whose top is at 6,634 feet above sea level. Subtracting the height from the elevation puts the ground it stands on at 5,663 feet. In extremely congested areas the FAA typically omits the parenthesized height to avoid confusion. A single unparenthesized figure is the elevation above sea level.

Two variations complete the set. Where obstacles stand close together, only the highest is represented, using the group obstruction symbol drawn as joined peaks. The legend's group forms cover at least two obstructions in the group, and the figures printed with the symbol belong to the highest one. Where a specialist cannot verify an obstacle's position or elevation, the letters UC print next to the symbol, meaning it is under construction or has been reported but not verified.

Obstacles may be lit or unlit. Where an obstruction carries a high-intensity strobe lighting system, the chart draws short rays radiating from the top of the symbol. The legend notes that such lights may operate part-time or by proximity activation. Mount Wilson prints no such rays, so its lighting is not the high-intensity kind. The lighting lesson covered the red obstruction lights that mark most structures at night. Wind turbines have their own symbol. A concentrated wind turbine farm is drawn as a hatched area with a dotted outline, and a boxed figure beside it gives the sea level elevation of its highest turbine. Turbine blades and blade tips are not lighted, and the lights sit on the nacelle, which in some cases is 200 to 300 feet below the rotating blade tips.

FAA Aeronautical Chart Users' Guide, "Land Features (Terrain) and Obstructions" and "VFR Symbology: Navigational and Procedural Information"

Navigation aids and visual checkpoints

The chart prints information about a radio aid to navigation, or NAVAID, inside a box. The type is identified by VOR, VORTAC, VOR-DME, or DME positioned on and breaking the top line of the box, and the box carries the facility name, the frequency, the TACAN channel where there is one, the identifier, and the identifier's Morse code. A NAVAID physically located on an airport may not always appear as the typical NAVAID symbol. Where one is collocated with an airport icon, a small open circle indicates its location.

A sectional chart excerpt of open desert dominated by a large blue circle about two-thirds the width of the frame. The circle's rim is graduated with fine tick marks and labelled at intervals with the numerals 0 at the top, then 3, 6, 9, 12, 15, 18, 21, 24, 27, and 33 running clockwise around it. At the center sits a small blue hexagonal navigation aid symbol. Below and left of the center, a boxed legend reads TWENTYNINE PALMS on its first line and 114.2, Ch 89, TNP followed by dot and dash groups on its second, with 122.1R printed above the box and a second smaller box below reading RIVERSIDE. An airport named TWENTYNINE PALMS with TNP in parentheses prints in magenta at the left with the numbers 1888, an asterisk L, 55, 122.8 and a circled C. A magenta hatched boundary labelled SUNDANCE MOA crosses the top left, a blue hatched boundary labelled R-2501E crosses the top right, and gray lines labelled IR216 and VR1263 cross the right side. — The Twentynine Palms VORTAC, with the full compass rose drawn around it. The rose is graduated in degrees and oriented to magnetic north, so a radial read from it is a magnetic bearing outbound from the station. The identification box gives the name, the frequency 114.2, the TACAN channel 89, and the identifier TNP with its Morse code. Los Angeles Sectional Aeronautical Chart, effective 9 July 2026 (FAA), cropped.

A compass rose is drawn around most VOR facilities. The Users' Guide states that the rose is a reference oriented to magnetic north. The numbers around the rim are therefore magnetic, the same reference your heading indicator and magnetic compass work in. Comparing a number from the rose with a heading on the panel requires no correction for magnetic variation. Each graduation is a radial, a magnetic bearing measured outbound from the station. DMEs are shown without a compass rose. Tuning a receiver to one of these facilities, identifying it, and tracking a radial belongs to VOR and GPS in Unit 10.

A magenta flag marks a VFR checkpoint, one of the visual checkpoints and landmarks the sheet carries for flight under VFR (AIM 9-1-5). Where the flag carries a name, an underline beneath the name indicates the proper name of the checkpoint. For high-traffic mountain passes, VFR checkpoints may be provided to increase situational awareness by marking key landmarks inside confined terrain. Some checkpoints have a VFR waypoint collocated with them, drawn as a four-pointed star with a five-character identifier beginning VP. Using those in a receiver is Unit 10 material as well.

FAA Aeronautical Chart Users' Guide, "Radio Aids to Navigation" and "VFR Symbology: Navigational and Procedural Information"; AIM 9-1-5

From the chart to the Chart Supplement

An airport data block is abbreviated because there is no room beside the symbol for more. The Chart Supplement U.S. carries the rest. It shows the data that cannot be readily depicted in graphic form, for example airport hours of operation, types of fuel available, runway widths, and lighting codes (AIM 9-1-5).

A black and white Chart Supplement entry for Chino, California. The heading line reads CHINO, then CNO and KCNO in parentheses, 3 SE, UTC minus 8, and a latitude and longitude, with LOS ANGELES at the right margin. Below it, 650 and the letter B and a line reading TPA dash See Remarks. Three indented blocks describe the runways in turn: RWY 08R dash 26L, H7000X150, ASPH dash GRVD, with strength figures and MIRL; RWY 03 dash 21, H4919X150; and RWY 08L dash 26R, H4858X150. Each runway end lists its PAPI, glide angle, threshold crossing height, and notes such as Rgt tfc or Trees. Further blocks are headed SERVICE, AIRPORT REMARKS, AIRPORT MANAGER with a phone number, WEATHER DATA SOURCES, COMMUNICATIONS listing CTAF 118.5, D dash ATIS 125.85 and UNICOM 122.95, then TOWER 118.5 and 120.125 with hours in parentheses, GND CON 121.6, and AIRSPACE reading CLASS D svc 1500 dash 0500Z, other times CLASS G. A small line drawing of the airport's three runways sits at the right. — The Chart Supplement entry for the same airport whose data block you just read. The numbers the chart compressed appear again here: elevation 650, CTAF 118.5, D-ATIS 125.85, UNICOM 122.95, and the longest runway, which the block gave as 70 and the entry prints as H7000X150. Chart Supplement U.S., Southwest volume, effective 9 July 2026 to 3 September 2026 (FAA), cropped.

Set the entry against the block. The chart said 70, meaning a longest runway of 7,000 feet. The entry says H7000X150 (ASPH-GRVD), which gives the 150 foot width, the asphalt surface, and the grooving. The same line gives the weight the pavement will bear and marks its edge lights as medium intensity. The chart said 118.5 with a star, which sent you to the tower frequencies tabulation for the hours. The entry prints them directly: TOWER 118.5 120.125 (Rwy 08R-26L) (1500-0500Z‡). The entry annotates the second frequency for runway 08R-26L, and the double dagger marks hours that run one hour earlier during daylight saving time. Below that line, AIRSPACE: CLASS D svc 1500-0500Z‡; other times CLASS G states what the airspace becomes when the tower closes. The chart said RP 3, 8L, 8R. The entry prints Rgt tfc. under each of those three runway ends. Its TPA line sends you to the remarks for the pattern altitude that the traffic pattern lesson covered.

The entry also carries what the chart has no room for at all:

the approach slope indicator on each runway end and the glide angle it is set to
the trees off two of those ends
the fuel grades available and the hours of self-service fuel
the airport manager's telephone number
the weather data source and its telephone number
the remark that radio-controlled aircraft operate below 400 feet above the ground two and a half miles south of the field

Read the entry in full before flying to an airport you have not used before.

AIM 9-1-5; Chart Supplement U.S., Southwest volume, Directory Legend and the Chino entry

The airport diagram and its hot spots

An airport diagram is a plan-view drawing of one airport's runways, taxiways, and ramps, specifically designed to assist in the movement of ground traffic at locations with complex runway and taxiway configurations. It is not intended for use in approach and landing or departure operations. It assists pilots in identifying their location on the airport, which reduces requests for progressive taxi instructions. A progressive taxi is a precise taxi instruction given to a pilot unfamiliar with the airport, or issued in stages as the aircraft proceeds along the taxi route (Pilot/Controller Glossary).

A black, white and gray airport diagram of Chino, California, printed in portrait format with the airport rotated so that north points toward the left edge and east toward the top. Three runways cross the field as solid black strips: 08R dash 26L labelled 7000 X 150, 03 dash 21 labelled 4919 X 150, and 08L dash 26R labelled 4858 X 150, each end carrying its magnetic heading. Five of the six ends print an elevation box reading ELEV 637, 636, 610, 617 or 620; at the runway 21 end a boxed FIELD ELEV 650 sits instead. Gray taxiways connect them to ramps at the left crowded with black hangar outlines. Taxiway letters A, B, C, D, E, F, H, J, K, L, M, N, P and Q are printed along the pavement. Three brown open circles are drawn where taxiways meet runways in the middle of the field, each leadered to a brown box reading HS 1, HS 2 and HS 3. A magnetic variation arrow at the upper left reads VAR 14 degrees E, and a stack of frequencies at the lower left reads ATIS, then 125.85, then CHINO TOWER followed by a star, then 118.5, then GND CON, then 121.6. Printed vertically down the right side is the caution: BE ALERT TO RUNWAY CROSSING CLEARANCES, READBACK OF ALL RUNWAY HOLDING INSTRUCTIONS IS REQUIRED. — The Chino airport diagram. The three brown open circles leadered to HS 1, HS 2, and HS 3 are the airport's hot spots. Each runway end carries its magnetic heading. Five of the six ends print their own elevation, and the boxed field elevation at the runway 21 end reads 650 feet. Each taxiway carries its letter. The frequency stack at the lower left repeats the ATIS, tower, and ground control frequencies, with a star marking the tower's part-time status. Airport Diagram, Chino (CNO), U.S. Terminal Procedures Publication, SW-3, effective 6 August 2026 to 3 September 2026 (FAA), cropped.

Airport diagrams are one of the five chart types that make up the U.S. Terminal Procedures Publication, alongside instrument approach procedure charts, departure procedures, standard terminal arrival charts, and charted visual flight procedure charts. Selected towered airport diagrams are also published in the airport diagram section of the Chart Supplement, in support of the FAA's Runway Incursion Program. That section's legend states that the diagrams there are the same as those published in the Terminal Procedures Publication. What the Chart Supplement prints inside an individual airport's entry is a smaller drawing than the airport diagram: an airport sketch, of the kind visible at the right of the Chino entry above.

The diagram carries:

the runways, complete with magnetic headings and identifiers, their dimensions, displaced thresholds, runway end elevations, surface composition, and weight bearing capacity
land and hold short lines, ILS hold lines, and localizer and glide slope critical areas
the taxiways with their identifiers
the parking areas, run-up pads, and non-movement areas
the control tower, the beacon, the lighting, and the navigation aids
the communications frequencies, where a star again indicates part-time status

A hot spot is a runway safety related problem area on an airport that presents increased risk during surface operations, typically a complex or confusing taxiway intersection or taxiway and runway intersection, as the markings lesson covered. Hot spots are indicated on the airport diagram with a brown open circle or ellipse leadered to a hot spot number, such as HS 1. Each number corresponds to a listing on the hot spot pages, which give a written description of what goes wrong there. The hot spot pages describe Chino's three:

pilots taxiing south on Taxiway D sometimes fail to turn onto Taxiway A and proceed onto Runway 08L-26R by mistake
pilots taxiing west on Taxiway L sometimes turn onto Runway 03-21 by mistake
after crossing Runway 21 westbound on Taxiway L, pilots sometimes confuse Taxiway D with Taxiway K and cross the 08L-26R holding position marking without authorization

Hot spots remain charted until the increased risk has been reduced or eliminated.

Read the diagram before the airplane moves The Chino diagram prints its own caution down the right margin: be alert to runway crossing clearances, and readback of all runway holding instructions is required. Trace your taxi route on the diagram before you call for taxi, and note which hot spot circles that route passes through. The air traffic control lesson covered the readback that a hold short instruction requires of you.

FAA Aeronautical Chart Users' Guide, Terminal Procedures Publication terms, "Airport Diagrams" and "Hot Spots"; Chart Supplement U.S., "Airport Diagrams" and "Airport Hot Spots"

What this unit has covered

This unit has covered:

the traffic pattern and the way a nontowered field is flown
the markings painted on the surface and the signs posted beside it
the lighting and the wake turbulence you keep clear of
the self-announced calls at a nontowered field
the clearances and instructions a tower issues
the chart and the publications that describe an airport before you see it

Unit 7 turns from the airport to the air itself: the structure of the atmosphere, how pressure and temperature produce wind, what makes air stable or unstable, and where clouds, icing, and thunderstorms come from.

Why this matters in the airplane

You make all four of these readings during planning, while there is still time to look up what a 1:500,000 sheet has no room to carry.

Read the airport's color before anything else. Blue means a control tower, magenta means none, and that single fact decides which radio procedure you use on arrival.
Check the RP line every time, and treat its absence as information only at a part-time towered or nontowered field. Right traffic patterns are not shown at airports with full-time control towers.
Take the maximum elevation figure as the highest elevation in the quadrangle, not as a safe altitude. Where terrain is the highest feature it already includes an allowance for source error and a 200 foot allowance for uncharted obstacles, and no figure is verified by field survey.
Open the Chart Supplement entry and the airport diagram for any airport you have not been to. The runway widths, the fuel, the tower hours, and the hot spots are not on the sectional at all.

Check your understanding

Answer from memory, without scrolling back up. Recalling it yourself is what makes it stick.

A sectional chart is drawn at what scale, and a new edition takes effect how often?

An airport whose symbol and printed data are magenta rather than blue?

Tick marks around an airport symbol, and a star beside it, mean?

A data block reads 650, then L, then 70, then 122.95. The 70 is?

In a data block, the star after the tower frequency and the circled C mark?

The notation RP 26 at the foot of an airport data block means?

The maximum elevation figure printed in a quadrangle of a sectional gives?

An obstruction prints 6634 with (971) below it. Those two figures are?

The compass rose printed around a VOR on a sectional is oriented to?

Hot spot circles are drawn on the airport diagram, which is published?

Go deeper (primary source): read the FAA Aeronautical Chart Users' Guide, starting with the VFR Terms and Symbols chapter and then the Sectional and Terminal Area Charts symbology pages, and compare each legend swatch against the same symbol on your own local sectional. Then read the Directory Legend at the front of your Chart Supplement volume in full, and the airport diagram legend in the Terminal Procedures Publication.

Stuck or curious? Bring your local sectional to your next lesson and ask your instructor to cover the legend, then have them point at six airports in turn and ask you to read each data block aloud, field by field, saying what the tower status, the field elevation, the lighting code, the longest runway, the CTAF, and the pattern direction are. Then pull up the airport diagram for the nearest towered field and ask them to trace the taxi route they would expect from the ramp to the runway, naming each hot spot the route touches.

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