Example – Calculation of SAT

In the previous lesson, we had understood the means of Calculating Static Air Temperature. In this lesson, let us look at an example of such calculation.

FORMULA BASED CALCULATION OF SAT (COAT)

  • RAT (IOAT) (Indicated Temperature) = -20°C
  • Mach No = M 0.73 (Normal Cruise Speed)
  • Recovery Factor (Kr) = 0.98 (From Flight Manual)
  • RAT of -20°C is 253 K
  • SAT = TAT / (1 + 0.2 Kr M²)
  • SAT = 253 + (0.2 × 0.98 × 0.73²) => SAT = 253/ (1 + 0.1044)
  • SAT = 253/ 1.1044 = 229 K => 229 K is -44°C on the Celsius scale.

Until now, we have understood the importance and methods of observing and calculating Outside Air Temperature measurement, In our next post, we shall focus our attention on Pressure Instruments.