Aeronautical charts are the “road maps” for VFR flight; they help pilots track position and enhance safety.
Three aeronautical charts used by VFR pilots:
Sectional
VFR Terminal Area Chart (VFR Terminal Area, sometimes called Terminal Area Chart)
World Aeronautical Chart
Chart catalog and ordering: Aeronautical Navigation Products website: www.aeronav.faa.gov
Sectional Charts
Scale: 1:500,000 (1 inch = 6.86 NM or ~8 statute miles)
Provide airports data, navigational aids, airspace, topography, and more; legend is essential for interpretation.
Legend includes ATC frequencies and airspace information; check for other legend details.
Revised semiannually (annually for some areas outside the conterminous U.S.).
VFR Terminal Area Charts
Scale: 1:250,000 (1 inch = 3.43 NM or ~4 SM)
Detailed topographical display; helpful in or near Class B airspace.
Revised semiannually; some Alaskan and Caribbean charts have different revision cycles.
World Aeronautical Charts
Scale: 1:1,000,000 (1 inch = 13.7 NM or ~16 SM)
Standard series for world coverage; symbols similar to sectional charts but less detail due to smaller scale.
Revised annually, with some Alaskan, Mexican, and Caribbean charts revised every 2 years.
Latitude and Longitude (Meridians and Parallels)
Parallels of latitude run east-west; measure degrees north/south of the equator.
Equator is 0°, poles at ±90°; US conterminous states roughly between 25° and 49° N.
Meridians (lines of longitude) run north-south from the North Pole to the South Pole; Prime Meridian (through Greenwich) is 0°.
Longitudes in the conterminous U.S. are roughly 67°W to 125°W; used to designate positions and time zones.
Time Zones
Earth rotates 360° in 24 hours → 15° per hour.
Standard time zones align with 15° longitude increments; U.S. conterminous time zones: Eastern (75°W), Central (90°W), Mountain (105°W), Pacific (120°W).
Noon corresponds to sun directly above a meridian; DST may shift the reference by +1 hour.
UTC (Zulu) time is 0° longitude; pilots convert local time to UTC for operations and communications.
Converting to UTC (example):
Eastern Standard Time (EST): add 5 hours to EST to get UTC
Central Standard Time (CST): add 6 hours
Mountain Standard Time (MST): add 7 hours
Pacific Standard Time (PST): add 8 hours
DST adjustments: subtract 1 hour from the calculated UTC times when DST is in effect.
For eastbound flights across zones, time calculations must consider sunset and daylight changes for planning.
Direction = True, Magnetic, and Compass Heading
True Course (TC): direction from a point to a destination measured clockwise from true north (TN).
Reciprocal course: TC + 180° (or TC − 180°).
Magnetic variations and compass considerations require converting true course to magnetic heading (MH) and compass heading (CH).
True heading (TH): nose direction relative to true north; may differ from TC due to wind.
Magnetic North (MN) vs. True North (TN) difference is the variation; need to add/subtract variation to obtain MH.
Variation (Magnetic Variation)
Variation is the angle between TN and MN.
Described as East or West variation:
If MN is east of TN, variation is East; if west, variation is West.
Isogonic lines connect points of equal magnetic variation; agonic line is where variation is zero.
Example: a variation of 9° East means MN is 9° east of TN; to convert TC to MH, subtract 9° (per rule: West variation = add; East variation = subtract). A mnemonic: “east is least (subtract), west is best (add)”.
Magnetic Variation, Compass Deviation, and Magnetic Heading
Variation: adjust TH to MH by adding/subtracting the local variation (use nearest isogonic line).
Deviation: local aircraft-induced offset of the compass due to metal, instruments, and systems; obtained from a compass deviation card and corrected to produce CH.
Swinging the compass: procedure to check and update deviation (set aircraft on MN on compass rose, record readings at 30° intervals, note changes for night operations).
Compass Heading (CH): MH corrected for deviation (MH ± D).
If a line shows variation of 9° East, then MH = TH − 9°; if variation is West, MH = TH + 9° (before applying deviation).
Wind and its Effect on Flight
Wind: air mass movement relative to the ground; affects GS (groundspeed) but not TAS (airspeed through the air).
Two motions when flying: movement of air mass relative to ground and aircraft’s movement through the air; combine to yield GS.
Groundspeed (GS) is the aircraft’s forward progress over the ground; Airspeed (TAS) is through the air.
Wind Triangle (Vector analysis): used to determine GS, heading, and time; foundation for dead reckoning.
Heading vs. Track:
Heading: the nose direction in the air (TH).
Track: actual path over the ground (drift due to wind).
Drift angle: the angle between heading and track.
Wind Correction Angle (WCA): angle to apply to the TC to counter wind drift so that the track aligns with the desired course.
If wind is from the left, drift pushes the aircraft to the right; heading must be adjusted to the left by WCA.
Wind Triangle: Practical Steps and Example
Step 1: Measure TC (true course) on chart.
Step 2: Use wind data to draw wind line; direction is wind from (e.g., 40 knots from NE, 045°).
Step 3: Draw airspeed line (TH) from departure at TAS (e.g., 120 knots).
Step 4: The intersection of the TAS line with the wind-adjusted TC line gives the ground track (GS) and the heading needed to maintain TC.
Example (from text): with TC 090°, wind from 045° at 40 knots, TAS 120 knots, estimate TH and GS; then determine TH to offset drift and compute MH and CH after applying variation and deviation.
Summary of Core Terms
Course: intended path over ground; direction of a line drawn on a chart; expressed as TC from TN.
Heading: direction the nose points; TH.
Track: actual path over the ground after wind effects; should match course with wind correction.
Drift angle: difference between heading and track.
WCA: wind correction angle applied to course to achieve desired track.
Airspeed (TAS): rate of progress through the air.
Groundspeed (GS): rate of progress over the ground.
Variation: difference between TN and MN; used to convert TH to MH.
Deviation: aircraft-induced compass error; used to convert MH to CH.
Basic Calculations (Preflight planning)
Time and distance relationships
Minutes to hours: divide by 60; e.g., 30 minutes = 0.5 hour.
Hours to minutes: multiply by 60; e.g., 0.75 hour = 45 minutes.
Time, Distance, and Ground Speed
Time: T = rac{D}{GS}
Distance: D=GSimesT
Ground Speed: GS = rac{D}{T}
Conversions: Knots to Miles Per Hour
1 knot = 1 NM per hour; 1 NM ≈ 1.15078 miles.
Approximate conversion: knots to mph ≈ multiply by 1.15; e.g., 20 knots ≈ 23 mph.
Fuel Planning
Fuel consumption typically in gallons per hour (gal/hr) or pounds per hour (lbs/hr) for jet fuel.
Specific range: NM per pound of fuel or NM per 1,000 pounds of fuel; used to estimate endurance and payload.
Preflight fuel planning must include cruise burn, startup/taxi, climb, and reserves.
Example: 400 NM trip at 100 knots GS; fuel rate 5 gal/hr; time = 4 hours; fuel needed = 4 × 5 = 20 gallons (assuming no wind).
Specific ranges and fuel planning considerations:
Turbine engines consume more fuel; jet fuel often quantified by density and volume to yield pounds-of-fuel-per-hour and NM per pound, etc.
Flight Computers and Plotting Tools
Flight Computers: mechanical E6B or electronic flight calculators; used for time, distance, speed, wind, fuel planning.
Plotter: protractor and ruler; used to determine TC and measure distance on charts; many plotters include NM/SM scales and chart scales.
Pilotage (Visual Navigation by Landmarks)
Pilotage uses prominent landmarks for position fixes; combine with dead reckoning and VFR radio navigation.
Choose checkpoints (roads, rivers, lakes, power lines) that bracket the route; avoid relying on a single checkpoint.
Sectional scale: 1 inch = 8 SM or 6.86 NM; use to estimate distances from course to features.
In congested areas, smaller features may not be depicted; if uncertain, hold heading.
Be aware of new roads and structures not depicted; antennas may be tall and require avoidance; many are marked with lights but can be difficult to see in certain conditions.
Dead Reckoning
Navigation by computations of time, airspeed, distance, and direction; wind is applied to derive heading and GS.
Wind triangle is the graphical representation; builds the basis for calculating GS, heading, and time en route.
VOR, NDB, GPS, ADF Navigation Aids (Ground-based Navigation)
VOR family (VOR, VOR/DME, VORTAC)
VOR provides magnetic bearings to/from the station; radials identified 001°–360° relative to MN.
Range depends on altitude; typical VOR reception at 1,000 ft AGL is ~40–45 miles; higher altitude increases range.
VOR classes: T (Terminal) up to 12,000' and 25-mile radius; L (Low) up to 18,000' and 40-mile radius; H (High) up to 14,500'–17,999' and 100-mile radius; Very High Altitude H up to FL450 and 130 miles, etc. (ranges vary with class and altitude)
Accuracy: generally ±1°; checks available via VOT, airborne checkpoints, or ground checkpoints; dual receiver checks ±4° between two VOR receivers.
CDI/HSI/RMI: indicators showing course deviation; TO/FROM indicator to determine whether to fly toward or away from the station.
VOR navigation steps: tune frequency, verify ident, center CDI on desired radial, fly headings toward or away from station per TO/FROM, and intercept/track the course.
The Horizontal Situation Indicator (HSI) combines compass with VOR information and glideslope; fixed aircraft symbol; deviation bar shows deviation from selected course.
RMI (Remote Magnetic Indicator): two bearing pointers driven by combinations of GPS, ADF, and/or VOR; can display multiple navigation sources.
NDB (Nondirectional Radio Beacon) and ADF
NDB transmits in low/medium frequency bands (roughly 200–415 kHz); some have long-range transmissions; signals follow the curvature of the Earth and are not line-of-sight dependent.
NDBs have varying usable ranges depending on power; listed classes: <25 W, 25–49 W, 50–1999 W, and 2000 W+ with corresponding ranges.
ADF displays bearing to the station; homing vs tracking; drift requires wind correction, particularly in crosswinds.
GPS and RNAV
GPS is a satellite-based navigation system with worldwide coverage; RNAV (VOR/DME RNAV) uses VOR/DME signals processed by an RNAV computer to provide direct routes using waypoints.
RAIM (Receiver Autonomous Integrity Monitoring) ensures signal integrity; minimum satellites required: typically 5 satellites for integrity, plus baro-aiding can reduce to 4 but isolate corrupt signals if possible.
SA (Selective Availability) degraded GPS performance historically; removed in 2000 but some units still assume SA present; users must verify database currency and integrity.
DME provides slant-range distance to VOR/DME or VORTAC; FPL/WP planning can use DME for GS and time-to-station.
VFR Waypoints
VFR waypoints are five-letter identifiers that begin with VP; used to supplement visual navigation and can be loaded into GPS or RNAV equipment.
Not intended for ATC communications; not a substitute for airspace requirements; should be loaded preflight, not programmed en route in flight.
On charts, stand-alone VFR waypoints are shown as a four-point star; collocated with a visual checkpoint marked by magenta flag; latitude/longitude data available in Chart Supplement U.S.
Filing and Using a VFR Flight Plan
Filing a flight plan is not mandatory but is good practice; helps search-and-rescue in case of emergency.
Filing can be done by phone or radio; FSS holds plan until 1 hour after proposed departure unless updated or canceled.
Information typically included: aircraft type, equipment, departure time (UTC/Zulu), cruising altitude, route, estimated time en route, fuel on board, NAVAIDs, etc.
Important fields (examples): aircraft type with equipment (e.g., C-150/X means no transponder), departure time in Zulu, cruising altitude (VFR), route (direct or via fixes), estimated time en route, fuel on board (hours:minutes).
Weather and Chart Supplements
Before flight, check weather to determine feasibility and route; see Aviation Weather Services for briefing.
Review Notices to Airmen (NOTAMs) and Chart Supplement U.S. for airports along the route; combine with sectional chart to assess latest information and potential hazards.
Chart Supplement U.S. provides details on airports (location, elevation, runways, services, fueling, NOTAMs), and tower frequencies; NOTAMs updated every 28 days.
Aircraft Weight, Balance, and Performance Planning
Use AFM/POH weight and balance data to determine empty weight, CG, payload, usable fuel, and takeoff/landing distances.
Heavier loads and higher elevation/temperature/humidity increase takeoff run and reduce climb rate.
Verify fuel consumption charts at estimated altitude and power settings to ensure adequate reserves.
Charting the Course (Flight Planning Example)
Example route: Chickasha to Guthrie (direct) with TAS 115 knots; winds aloft 360° at 10 knots; usable fuel 38 gallons; fuel rate 8 GPH; deviation +2°.
Steps in planning include: drawing a straight course line; identifying checkpoints; checking airspace (Class C around Will Rogers World Airport; Class D around Wiley Post Airport during tower operation); evaluating terrain elevations and tallest obstructions; selecting cruising altitude that provides safe clearance above terrain and airspace, and adheres to Part 91 odd-thousand-plus-500-ft rule for magnetic courses between 0 and 179°.
Determine total distance (53 NM in example) and check checkpoints around the route; TC line measured with plotter; TH calculated with WCA and variation and deviation corrections to CH.
Example calculations from figure notes:
TC = 031°; Winds 360° at 10 knots; TAS = 115 kn; Deviation = +2°; WCA calculated as 3° left; TH = 28° after applying WCA; Variation is 6.3° E (rounded to 7° E) → MH = 21°; Deviation +2° → CH = 23°; GS calculated as 106 knots; total time about 35 minutes; fuel about 38 gal final planning figures.
Data Sheet and Log (Flight Log)
Pilot’s planning sheet includes TC, TH, MH, DEV, CH, GS, wind, and wind correction factors; summarized with total miles and elapsed time.
Time, Distance, and Performance Checks
Time to destination, leg times, and fuel usage can be estimated from the planning sheet and confirmed during flight with actual GS and winds.
Weather Briefing and Preflight Material
Before flight, obtain weather briefings; verify NOTAMs; check NOTAM and chart supplements for hazardous conditions or airspace restrictions.
In-Flight Procedures: Navigation Fundamentals
Pilotage and dead reckoning are foundational navigation techniques; pilots should be proficient with the wind triangle and RNAV/VOR tracking.
Never rely on a single navigation method; always cross-check with other navigational aids and pilotage references.
Lost Procedures, Diversion, and Risk Management
If lost, climb to improve reception; use navigational aids to determine position; contact FSS or ATC for vectors; use 121.5 MHz in emergencies.
Diversion planning: preselect alternates, evaluate capabilities, and minimize head-down time; balance time, fuel, weather, and terrain when diverting.
Chapter Summary (Key Takeaways)
Fundamentals of Visual Flight Rule navigation, chart usage, and GPS integration.
Planner responsibilities: preflight planning, weather, NOTAMs, airspace, fuel planning, weight and balance, and flight logs.
Emphasis on planning and executing plan with safety and situational awareness; understanding of charts, airspace, weather, and navigation aids.
Formulae and Key Concepts (quick reference)
Time, Distance, and Ground Speed
Time: T=GSD
Distance: D=GS×T
Ground Speed: GS=TD
Conversions
Minutes to hours: divide by 60; hours to minutes: multiply by 60
Knots to mph: 1kn=1.15mph
Wind Correction and Navigation (concepts)
True Course (TC): direction on chart from true north
Wind Correction Angle (WCA): angle to add/subtract to TC to offset wind drift
True Heading (TH): TC adjusted by WCA to counter drift
Variation (VAR): angle between TN and MN; applied to TH to obtain Magnetic Heading (MH)
Deviation (D): compass error unique to aircraft; MH adjusted by D to obtain Compass Heading (CH)
CH is the heading the pilot actually flies to stay on course when wind is present
Drift angle: the angle between heading and track (drift caused by wind)
Variation Sign Convention
If variation is West, add to TH to get MH; if variation is East, subtract from TH to get MH. A common mnemonic: “east is least (subtract) and west is best (add)”
VOR Navigation (basic indicators)
CDI (Course Deviation Indicator): indicates deviation from the selected VOR course; TO/FROM indicator shows whether the selected course leads toward or away from the station
HSI (Horizontal Situation Indicator): integrates compass and navigation signals; fixed aircraft symbol; deviation bar shows deviation from the selected course
RMI (Radio Magnetic Indicator): dual bearing pointers for multiple navaids (VOR, GPS, ADF)
RNAV and DME RNAV
RNAV enables waypoints that are defined by a radial and distance from a VORTAC; en route and approach modes; CDI displays guidance to the waypoint rather than the VORTAC
DME provides slant-range distance to the VORTAC/VOR-DME station; GS and time-to-station are available in many units
ADF and NDB
ADF navigates to NDBs; bearing to station displayed on NDB indicator; homing vs tracking; wind drift requires corrections
GPS RAIM and SA
RAIM ensures integrity of GPS position; minimum satellites vary by receiver; baro-aiding and multiple satellites improve integrity; SA was deactivated but some receivers still assume it
VFR Waypoints
Five-letter VP identifiers; used to augment VFR navigation; not used for ATC communications; plan and load prior to flight
Notable Examples from the Material
Wind Triangle Example Summary: If TC is 090°, TAS 120 knots, wind from 045° at 40 knots, you would construct a wind triangle to determine TH and GS; then derive WCA to align TH with TC and adjust for variation and deviation to obtain CH for navigation.
Chickasha to Guthrie Example (Figure 16-26/16-26 era):
TAS = 115 kn; Winds aloft 360° at 10 kn; Usable fuel 38 gal; Fuel rate 8 GPH; Deviation +2°
TC = 031°; WCA ≈ 3° left; TH ≈ 28°; Variation ≈ 7° East → MH ≈ 21°; Deviation +2° → CH ≈ 23°; GS ≈ 106 knots; Total distance 53 NM; Total time ≈ 0:35; Fuel ≈ 38 gal (example values).
Preflight planning steps (as per Figure 16-26): chart the route on the sectional, identify checkpoints, evaluate airspace, terrain, and obstructions; determine altitude that ensures clearance (e.g., 5500 ft MSL for Class C and D considerations in the example); compute distance and TC; compute TH and CH; calculate GS and ETA; estimate fuel usage
VOR/NAVAID Checks and Use:
Validate station ident with Morse or voice ID; ensure signal strength; use TO/FROM correctly; maintain intercept heading to avoid overshooting; ensure proper identification to avoid misnavigation.
DME provides distance to station, enabling precise position fixes when RNAV is used
GPS Use Guidance (VFR):
Always verify RAIM capability and database currency; do not rely solely on GPS for navigation; be prepared for signal outages; understand moving map displays if the unit has a current database; verify waypoints with official sources; plan flights to minimize head-down time; ensure proper mounting location for antenna
Loss, Diversion, and Risk Management in flight planning
Prepare for alternate airports and ability to divert for hazardous weather; use onboard tools to estimate new arrival times and fuel; prioritize safety and crew workload
VFR Filing and ATC Interaction
Filing a VFR flight plan is voluntary but advantageous for SAR; file with FSS and provide information in order; close the plan on arrival
Flight Planning Documentation
Flight planning sheet (Figures 16-26 and 16-27) includes course data, wind, altitude, checkpoints, and time estimates; the sample form includes fields for course, TC, TH, MH, CH, GS, wind, WCA, and total distance and fuel
Connections to Foundational Concepts and Real-World Relevance
Plotting and chart interpretation are foundational to safe visual navigation; understanding chart scales, legend abbreviations, and airspace boundaries is essential for planning and safe execution.
The wind triangle is a fundamental concept for any navigation, providing a framework to understand heading, track, wind, and ground speed. Mastery allows accurate ETAs and fuel planning.
Magnetic variation and compass deviation are practical realities of instrument-based navigation; pilots must know how to convert charted true courses to magnetic/compass headings and apply corrections to maintain course using real instruments.
Ground-based navigation aids (VOR, NDB, ADF) and GPS RNAV systems complement pilotage and dead reckoning. The pilot should be proficient in combining multiple navigation sources to validate position and route.
Weight and balance, weather, NOTAMs, and CHART SUPPLEMENT U.S. considerations directly impact takeoff and landing performance, route safety, and diversion options.
Ethical and practical implications: safe planning, require compliance with 14 CFR Part 91; ensuring backups and cross-checks in navigation reduces risk of disorientation or loss of the aircraft; emphasize not relying solely on GPS; maintain situational awareness through pilotage and dead reckoning in case of radio/navigation equipment failure.
Quick Reference: Symbols and Figures Mentioned
Sectional, VFR Terminal Area, World Aeronautical charts and their scales
Latitude/Longitude grid and Prime Meridian (Greenwich)
Isogonic lines (magnetic variation) and agonic line (zero variation)
Wind triangle diagrams (TH, WCA, TC, GS) and step-by-step wind triangle construction (including example steps)
Plotter instructions (Figure 16-18)
VOR indicators: CDI, TO/FROM, HSI, RMI (Figures 16-29 to 16-32)
RNAV and VORTAC/DME (Figure 16-35 to 16-36)
ADF indicators and ADF tracking (Figures 16-37 to 16-39)