Aeronautical Charts and VFR Navigation

Overview of VFR Aeronautical Charts and Sectional Charts

Primary Purpose: Sectional charts are designed for pilots flying under Visual Flight Rules (VFR).
Navigation Type: The primary form of navigation used with these charts is pilotage, which involves a pilot knowing their location based on visual recognition of landmarks and features on the ground.
Visual Recognition Examples: * Recognizing specific highways, such as $I-35$ . * Identifying local landmarks, such as the Riverwind Casino or the Devon Tower in Downtown Oklahoma City. * Using the symbology on the sectional chart to identify unfamiliar terrain or areas.
Common Scale: Sectional charts are produced at a scale of $1:500,000$ .
Standardized Size: Charts are produced in a common size by geographic regions of the country.
Update Cycle: Sectional charts are updated every $56$ calendar days. This was previously an every-six-month update cycle, but it has been adjusted to align with the schedules of other aeronautical charts.
Regional Classification: Charts are named based on the major geographic area they cover. * Example: The Dallas-Fort Worth sectional covers a significant portion of North Texas, parts of the Texas Panhandle, and Southern, Western, and Eastern Oklahoma.
Inter-Chart Planning: Because the country is split into regions, pilots often need multiple charts for a single trip. * Example Scenario: A flight from Norman, Oklahoma, to Peachtree De Kalb Airport (Atlanta area) would require the Dallas-Fort Worth sectional to start, the Memphis sectional for the next portion of the route, and the Atlanta sectional for the final arrival.
Identifying Adjoined Charts: Every sectional chart includes a geographic area chart on the back to help pilots identify which neighboring charts are necessary for route planning.
Terminal Area Charts (TAC): Represented on the sectional index as small magenta boxes, these charts provide greater detail for areas with complex Class Bravo airspace.

Maximum Elevation Figures (MEF) and Topography

Maximum Elevation Figure (MEF): Every little quadrangle (bounded by black lines with hashes) on a sectional chart contains a large number representing the MEF. * Purpose: The MEF is designed to prevent pilots from colliding with the tallest object in that specific geographic area. * Calculation Methodology: The MEF is determined by taking the highest known feature (terrain or obstruction) in the quadrangle, adding $100$ feet, and then rounding up to the nearest hundred. * Example Local Values: * East of Norman (Lake Thunderbird area): $2200$ feet. * Shawnee/Seminole area (east of the Norman quadrangle): $1700$ feet. * West of Norman: $2200$ feet. * Further West: $2300$ feet.
Topography Representation: Sectional charts use color coding and contour lines to display the rise and fall of terrain. * Color-Coded Elevation: Colors change every $1,000$ feet of elevation. * Light bluish-green: $0$ to $1,000$ feet Mean Sea Level (MSL). * Darker green: $1,000$ to $2,000$ feet MSL. * Brownish/tan shades: $2,000$ to $3,000$ feet MSL and above as elevation increases (specifically seen toward West Texas and the Caprock). * Contour Lines: These represent specific elevation intervals. * Standard interval: $500$ feet. * Special intervals: In extremely flat areas (e.g., Northern Louisiana where the highest point is roughly $330$ feet) or rapidly rising terrain (e.g., the Rocky Mountains around Taos or Angel Fire, New Mexico), contour lines may be marked every $250$ feet.

Airport Symbology and Legend Details

Color Coding for Control Towers: * Blue: Indicates an airport with an operating control tower (at least part-time). * Magenta: Indicates non-towered airports.
Runway Depiction: * Open Circle (No Runway Silhouettes): Indicates the airport does not have a hard-surface runway. * Runway Silhouettes Inside Circle: Indicates a hard-surface runway between $1,500$ feet and $8,069$ feet in length. The silhouette shows the general configuration of the runways. * Outlined Runway (No Circle): Used for airports with at least one hard-surface runway longer than $8,069$ feet. These are outlined in blue (towered) or magenta (non-towered) to show the actual runway configuration.
Special Facility Symbols: * R: Private airport. * Double Circle: Military airport. * H: Helipad. * U: Unverified airport (sketchy information regarding the site). * Circle with an X: Abandoned field or decommissioned airport. * Example: The old Oklahoma City Downtown Air Park, decommissioned in the late $1980$ s/early $1990$ s, now near an OKC sign and Ferris wheel. * Circle with an F: Ultralight flight park. * Notches around the circle (at 12, 3, 6, and 9 o'clock positions): Indicates the availability of fuel services. * Anchor: Seaplane base. * Star (above the airport symbol): Indicates a rotating beacon is present. * At major airports with runways over $8,069$ feet, the star is placed near the beacon's actual physical location relative to the runways. * Dot inside the airport circle: Indicates a VOR or VORTAC is co-located on the airport field (e.g., Wiley Post Airport). * Objectionable: A notation for an airport that may adversely affect airspace use or violates FARs.

Airport Data Tags and Frequencies

Components of an Airport Tag: * Official Name and Identifier: (e.g., University of Oklahoma Westheimer, identifier $OUN$ ). * Flight Service Station (FSS): Usually noted if it serves that specific area. * Tower Frequency: Highlighted in blue (e.g., Westheimer is $118.0$ ). * ATIS/AWOS: Frequencies for automated weather (e.g., Westheimer AWOS is $119.55$ , Tulsa Riverside ATIS is $126.5$ ). * Field Elevation: Measured in feet MSL (e.g., Westheimer is $1182$ feet; David J. Perry is $1169$ feet). * Lighting: A letter "L" indicates the runway has lights. * Runway Length: Shown in hundreds of feet (e.g., $52$ represents $5,200$ feet). * Unicom/CTAF: (e.g., $122.95$ or $122.7$ ). The letter "C" in a circle denotes the Common Traffic Advisory Frequency.
Traffic Patterns: Symbols or notes indicate non-standard patterns. * Example: "RP 18, 21" at Westheimer means right-hand traffic for Runways $18$ and $21$ to avoid overflying other runways or local noise-sensitive areas. * Example: Palo Alto uses right-hand traffic for Runway $31$ to keep aircraft over the bay rather than over expensive Residential properties.

Airspace Classifications on Charts

Class Bravo (B): Outlined with solid blue lines. Altitudes are shown as a fraction (e.g., $100/30$ means the floor is $3,000$ feet and the ceiling is $10,000$ feet). Floors can be staggered in a "wedding cake" fashion.
Class Charlie (C): Outlined with solid magenta lines. Usually consists of a $5$ -mile inner circle (surface to $4,000$ feet above airport elevation) and a $10$ -mile outer shelf (starting at $1,200$ feet). * Example: Tulsa Class C has an upper limit of $4,700$ feet MSL because the field is at $678$ feet (rounded to $700$ plus $4,000$ ). * Example: Oklahoma City's Class C has a "VFR Corridor" over $I-35$ where the shelf floor is higher ( $3,000$ feet) allowing pilots to stay below it at $2,500$ feet.
Class Delta (D): Outlined with a dashed blue line. Typically a $5$ -mile radius from the surface to a specified altitude in a segmented box. * Example: Tulsa Riverside Class D ceiling is $3,100$ feet ( $638$ foot elevation rounded down to $600$ plus $2,500$ ). * Example: Westheimer Class D ceiling is $3,700$ feet ( $1,182$ foot elevation rounded to $1,200$ plus $2,500$ ).
Class Echo (E): Transition areas from $700$ feet or $1,200$ feet AGL are shown with faded magenta or blue shading.

Navigational Aids (NAVAIDs) and Communication Boxes

VOR (VHF Omnidirectional Range): Represented as a hexagon.
VOR-DME: A hexagon inside a square box.
VORTAC: A hexagon with three dark tabs ("Mickey Mouse ears") and a small line below ("goatee").
NDB (Non-Directional Beacon): A series of magenta dots in a circular pattern. * If co-located at an airport, the dots surround the airport symbol (e.g., Henrietta).
Communication Boxes: Boxes containing the NAVAID name, frequency, identifier, and Morse code. * Example: Will Rogers VORTAC ( $IRW$ ) on frequency $114.1$ .

Visual Landmarks, Hazards, and Features

Obstructions (Antennas): * Single Chevron: Obstruction less than $1,000$ feet AGL. * Double Chevron: Group of obstructions less than $1,000$ feet AGL. * Elongated Tower Symbol: Obstruction taller than $1,000$ feet AGL (e.g., the TV towers on Bruton Road). * Dot inside Symbol: Indicates the obstruction is lighted. * Lightning Bolts/Arcs: Indicates high-intensity white strobe lights. * Elevation: Expressed in MSL (bold) and AGL (smaller text in parentheses).
Other Visual Indicators: * Power Lines: Depicted as lines with small cross-marks. * Wind Turbines: Areas with wind farms are hashed out; the elevation for the highest turbine is noted (e.g., $2152$ feet near Minco). * Parachute Activities: Indicated by a parachute symbol (e.g., near Chickasha or Bolivar). * Glider Areas: Depicted as a glider symbol (e.g., near Hinton). * Visual Reporting Points: Small magenta flags used for VFR arrival into busy areas (e.g., Inola, Coweta, Leonard, or Bixby for Tulsa). * Special Use Airspace: Includes Restricted Areas, MOAs (Military Operations Areas), and military training routes ( $VR$ for Visual Routes and $IR$ for Instrument Routes). * Aviation-Specific Locations: Clinton Sherman is an approved Spaceport, indicated by a rocket ship symbol.

Questions & Discussion

Question (Brandon): "Is the facility's longest runway $7200$ [at Muskogee]?"
Answer: "Let's take a look. It does say $7200$ , so that would be less than $8,069$ . It probably has an area that has been decommissioned… but part of that runway may be decommissioned, which is why now it’s $7200$ ."
Identification Exercise (Student Responses): * Symbol 1: Power lines (Landon). * Symbol 2: Magenta circle around Class C airspace (Taylor). * Symbol 3: Heliport (Brendan). * Symbol 4: Towered airport with hard runways, fuel available, length between $1,500$ and $8,069$ feet (Hayden). * Symbol 5: Parachute activity (Lucas). * Symbol 6: Upper limit of Class C airspace ( $4,000$ feet AGL) (Crandon). * Symbol 7: Non-towered airport, runway $1,500$ to $8,069$ feet, no fuel, no beacon (Way). * Symbol 8: Towered airport with runway greater than $8,069$ feet (Lily). * Symbol 9: Nondirectional radio beacon (NDB), not on an airport (Maddie). * Symbol 10: Rotating beacon at a towered airport (Jackson). * Symbol 11: Group of antennas taller than $1,000$ feet MSL, lighted, but no high-intensity lights (Jacob). * Symbol 12: Towered airport, runway $1,500$ to $8,069$ feet, no fuel, no beacon (Marty). * Symbol 13: Towered airport with a VOR-DME and at least one runway longer than $8,069$ feet (Lance). * Symbol 14/15: Victor airway $69$ following radial $132$ . The number $169$ in the box indicates the airway is $169$ miles long from NAVAID to NAVAID (Tabby/Spencer). * Symbol 16: Lighted tower with high-intensity lights, height less than $1,000$ feet (Andrew).