liminfoE6B Flight Computer
Free web tool: E6B Flight Computer
Ground Speed
119.1 kts
Wind Correction Angle
-7.2°
About E6B Flight Computer
The E6B Flight Computer is a free browser-based aviation planning tool that covers two essential pre-flight calculations: wind correction and fuel planning. The wind correction tab takes your True Airspeed (TAS) in knots, desired heading in degrees, wind direction (the direction the wind is blowing FROM), and wind speed in knots. It uses the wind triangle sine-rule to compute the Wind Correction Angle (WCA), the resulting ground speed, and the adjusted true heading to fly. All four inputs are shared between tabs so you only need to enter wind data once.
The fuel planning tab extends the wind correction results by adding distance (nautical miles), fuel burn rate (gallons per hour), and fuel onboard (gallons). Using the ground speed already computed from your wind inputs, the calculator derives flight time in minutes, fuel required for the trip, total endurance in minutes, and fuel reserve remaining after reaching the destination. If the reserve is negative — meaning you do not have enough fuel — the reserve card turns red as an immediate visual warning, making this tool valuable for pre-flight go/no-go decisions.
This tool targets student pilots preparing for FAA written exams and recreational VFR pilots who want a quick, convenient digital replacement for the mechanical E6B circular slide rule or flight planning apps that require account creation. The entire calculation runs locally in your browser — no data is transmitted to any server. The interface is bilingual (Korean and English) and supports dark mode for night operations.
Key Features
- Wind triangle solver: computes WCA, adjusted true heading, and ground speed from TAS, heading, wind direction, and wind speed
- Fuel planning module: calculates flight time, fuel needed, total endurance, and reserve fuel using ground speed and burn rate
- Shared wind inputs — enter TAS, heading, and wind data once and use them across both the wind and fuel tabs
- Red/green visual indicator on fuel reserve — red warning when calculated reserve is negative (insufficient fuel)
- Real-time calculation: all outputs update instantly without pressing a button
- Ground speed derived from wind triangle feeds directly into fuel time calculation for consistency
- Maximum range estimation based on fuel onboard and computed ground speed
- 100% client-side processing — suitable for pre-flight planning without internet access
Frequently Asked Questions
What is the difference between the E6B Flight Computer and the E6B Flight Calculator on this site?
The E6B Flight Computer (this tool) focuses on wind correction and fuel planning for a specific flight leg: it calculates flight time, fuel needed, endurance, and remaining reserve. The E6B Flight Calculator on this site focuses on wind correction and density altitude — the atmospheric performance calculation needed for takeoff safety. Both tools use the same wind triangle math but serve different pre-flight planning purposes.
How is ground speed used in fuel planning?
Ground speed is the speed of the aircraft over the ground, accounting for wind effects. Flight time = Distance / Ground Speed. Once flight time is known, fuel needed = Flight Time × Fuel Burn Rate. A headwind increases flight time and fuel burn; a tailwind decreases both. This is why wind inputs are shared between the wind correction and fuel planning tabs — the ground speed from your wind calculation is automatically used in the fuel calculation.
What is fuel endurance and how does it differ from range?
Fuel endurance is the maximum time an aircraft can fly on its current fuel supply at the specified burn rate: Endurance = Fuel Onboard / Burn Rate. Maximum range is the farthest distance the aircraft can travel: Range = Ground Speed × Endurance. Endurance is a time-based measure; range is distance-based. Both assume constant burn rate and ground speed with no reserve.
Why does the fuel reserve card turn red?
The reserve card shows Fuel Reserve = Fuel Onboard − Fuel Needed for the specified route. If this value is negative, you do not have enough fuel to reach your destination with the filed fuel load, and the card turns red. FAA regulations require VFR daytime flights to carry enough fuel to fly to the first intended landing and then at least 30 minutes more. A negative reserve means you must either add fuel, reduce distance, or choose a closer destination.
What units does this calculator use?
Airspeed and wind speed are in knots (nautical miles per hour). Heading and wind direction are in degrees (0–360, where 360 is due north). Distance is in nautical miles (nm). Fuel burn rate and onboard fuel are in US gallons. Flight time and endurance are in minutes. These are the standard units used in general aviation flight planning in the United States.
How accurate is the wind correction angle calculation?
The WCA is computed using the exact trigonometric formula: WCA = arcsin(wind speed × sin(wind direction − heading) / TAS). This is the same mathematical solution used in flight simulation software and is more precise than the graphical E6B slide rule, which introduces small mechanical reading errors. For exam study purposes, the results match FAA-published answer key values within rounding tolerance.
Can I use this for multi-leg flight planning?
This tool calculates one flight leg at a time. For multi-leg routes, calculate each leg separately using the appropriate distance, wind, and fuel values for each segment. You can use the reserve fuel from one leg as the starting fuel onboard for the next leg to track cumulative fuel usage across a complete route.
What TAS should I use for a Cessna 172 or similar aircraft?
A typical Cessna 172 cruises at approximately 110–122 knots TAS at 2,500–3,500 ft, depending on power setting and altitude. At higher altitudes, TAS increases above indicated airspeed due to lower air density. For pre-flight planning, use the cruise TAS from your aircraft Pilot Operating Handbook for the planned altitude. A common planning value is 110 knots for normal cruise.