True Airspeed Calculator
Calculate true airspeed (TAS) from indicated airspeed, altitude, and temperature for accurate flight planning.
Calculator
Flight Parameters
Results
Where ρ₀ is sea level density and ρ is density at altitude
About True Airspeed
What is True Airspeed?
True Airspeed (TAS) is the actual speed of an aircraft through the air mass. It differs from Indicated Airspeed (IAS) due to altitude and temperature effects on air density.
Why is TAS Important?
TAS is essential for navigation, fuel planning, and flight time calculations. GPS ground speed equals TAS when there's no wind component.
Key Factors
- Higher altitude = Higher TAS (lower air density)
- Higher temperature = Higher TAS (lower air density)
- At sea level in standard conditions: TAS ≈ IAS
Aviation Standards
- Standard temperature: 15°C at sea level
- Standard lapse rate: -2°C per 1000 ft
- Calibrated airspeed assumes minimal instrument error
Quick Reference
True Airspeed Regulatory Requirements
FAA Requirements (United States)
14 CFR 91.117 - Aircraft Speed
Establishes maximum operating speeds for aircraft operations in controlled airspace, based on indicated airspeed which must be converted to true airspeed for navigation purposes.
14 CFR 91.159 - VFR Cruising Altitude
Requires pilots to maintain appropriate VFR cruising altitudes, where true airspeed calculations are essential for flight planning and fuel consumption estimates.
AC 00-45H - Aviation Weather Services
Provides guidance on using atmospheric data for flight planning, emphasizing the importance of true airspeed in wind triangle calculations.
EASA Requirements (Europe)
SERA.6001 - VMC Visibility and Distance from Cloud Minima
Requires pilots to maintain specific flight conditions where true airspeed calculations affect compliance with visibility and cloud clearance requirements.
SERA.5005(f) - Pre-flight Action
Pilots must determine estimated times en route and fuel requirements, calculations that depend on accurate true airspeed computations.
Navigation Applications
Wind Triangle Solutions
- Ground speed calculations for flight planning
- Wind correction angle determinations
- Fuel consumption estimates
- Time en route calculations
Performance Planning
- Optimal altitude selection
- Range and endurance planning
- Approach speed calculations
- Emergency descent planning
Professional Best Practices
Calculation Accuracy
- Use current altimeter setting
- Account for temperature variations
- Verify pressure altitude readings
- Cross-check with GPS ground speed
Flight Planning
- Calculate TAS for each flight segment
- Factor in altitude changes
- Consider temperature deviations
- Update calculations en route
Safety Considerations
- Maintain adequate fuel reserves
- Monitor actual vs. planned speeds
- Account for changing conditions
- Use conservative estimates