ISA Temperature Calculator

Formulas

The formula to calculate the ISA Temperature Difference (ISA T) is:

\[ \text{ISA T} = \text{ST} - \text{AT} \]

Where:

\( \text{ISA T} \) is the ISA Temperature Difference (°C)
\( \text{ST} \) is the Standard Temperature at the given altitude (°C)
\( \text{AT} \) is the Actual Temperature reading (°C)

The formula to calculate the Standard Temperature (ST) at a given altitude is:

\[ \text{ST} = 15 - 1.98 \times \frac{\text{A}}{1000} \]

Where:

\( \text{ST} \) is the Standard Temperature (°C)
\( \text{A} \) is the Altitude (ft)

What is ISA Temperature?

An ISA temperature is a measure of the difference between the actual temperature reading on an aircraft and the standard temperature at that altitude. It helps in understanding how current atmospheric conditions compare to the International Standard Atmosphere (ISA) model.

Example Calculation

Let's consider an example:

Altitude (A): 5000 ft
Actual Temperature (AT): 10 °C

Using the formula to calculate the Standard Temperature:

\[ \text{ST} = 15 - 1.98 \times \frac{5000}{1000} = 15 - 9.9 = 5.1 \, \text{°C} \]

Now, calculate the ISA Temperature Difference:

\[ \text{ISA T} = 5.1 - 10 = -4.9 \, \text{°C} \]

This indicates that the actual temperature is 4.9 °C warmer than the standard temperature at 5000 ft altitude.