Ground Speed Calculator
Calculate aircraft ground speed, wind correction angle, and heading for aviation navigation
Calculate Aircraft Ground Speed
Aircraft speed relative to surrounding air
Wind speed relative to ground
Desired flight path (clockwise from North)
Direction wind is blowing TO (not FROM)
Navigation Results
Ground Speed Formula: vg = √(va² + vw² - 2×va×vw×cos(θ))
Wind Correction Angle: α = arcsin(vw×sin(ω-δ)/va)
Heading: ψ = δ + α
Wind Effect Analysis
Example Calculation
Commercial Flight Example
Aircraft: Boeing 737 en route from New York to Boston
True Airspeed: 450 knots
Wind: 50 knots from 270° (west wind)
Desired Course: 090° (due east)
Wind Direction: 270° (blowing TO the east)
Calculation Steps
1. Wind Correction Angle: α = arcsin(50×sin(270°-90°)/450) = arcsin(-0.111) = -6.4°
2. Heading: ψ = 90° + (-6.4°) = 83.6°
3. Ground Speed: vg = √(450² + 50² - 2×450×50×cos(180°)) = √(202500 + 2500 + 45000) = 500 knots
Result: Tailwind gives 50 knots speed boost!
Quick Flight Scenarios
Commercial Airliner
Light Aircraft
Fighter Jet
Helicopter
Aviation Terms
True Airspeed
Aircraft speed relative to air mass
Ground Speed
Speed over ground surface
Wind Correction Angle
Angle to offset wind drift
Heading
Direction aircraft points
Wind Types
Tailwind
Increases ground speed
Headwind
Decreases ground speed
Crosswind
Requires heading correction
No Wind
Ground speed = True airspeed
Understanding Ground Speed in Aviation
What is Ground Speed?
Ground speed is the horizontal velocity of an aircraft relative to the Earth's surface. Unlike true airspeed (which measures speed relative to the air mass), ground speed determines how fast the aircraft travels over the ground and directly affects flight time.
Why Ground Speed Matters
- •Determines actual flight duration
- •Affects fuel consumption calculations
- •Critical for navigation and flight planning
- •Essential for arrival time estimates
Ground Speed Formula
vg = √(va² + vw² - 2×va×vw×cos(θ))
- vg: Ground speed
- va: True airspeed
- vw: Wind speed
- θ: Angle between aircraft heading and wind direction
Note: This formula is derived from vector addition using the law of cosines.
True Airspeed vs Ground Speed
True Airspeed (TAS)
- • Speed relative to surrounding air
- • Important for aircraft performance
- • Determines lift and flight characteristics
- • Increases with altitude (lower air density)
Ground Speed (GS)
- • Speed relative to Earth's surface
- • Determines flight duration
- • Affected by wind conditions
- • Independent of altitude
Wind Correction Angle
α = arcsin(vw × sin(ω - δ) / va)
The wind correction angle is the amount a pilot must adjust the aircraft's heading to maintain the desired course in the presence of crosswind.
Key Points
- • Positive angle: correct to the right
- • Negative angle: correct to the left
- • Larger crosswinds require larger corrections
- • Essential for maintaining course accuracy