Verify before flight. Check the POH/AFM for aircraft-specific limits and performance.
Performance
True Airspeed (TAS) Estimate Calculator
Estimate true airspeed from calibrated airspeed and pressure altitude using the common 2% per 1,000 ft training rule.
kt
ft
Approx. TAS—
Increase over CAS—
CAS—
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The 2% shortcut at 8,000 feet
Using the 2% shortcut, 110 kt CAS at 8,000 ft increases by 16%: 110 × 1.16 = 127.6 kt estimated TAS.
This shortcut omits actual temperature and compressibility corrections. Use an appropriate air-data method or aircraft information when accuracy matters.
Formula and method
The 2% rule estimates TAS by increasing CAS about 2% per 1,000 feet. It is a training shortcut, not a precision air-data solution.