Note: If you are comparing the results with most flight computers you should uncheck this box.

Example 1:

You are flying at a pressure altitude of 7620 ft, your temperature gauge which is corrected to show true air temperature, reads 4.6 ^oC. If your true airspeed is 195 knots, what is your true airspeed?

First let's list the information we have:

     1) PA = 7620 ft (if you have calibrated altitude and altimeter setting instead, click here
          to see how to calculate pressure altitude)
     2) T = 4.6 ^oC
     3) IAS = 195 knots

We have three of the four variables for the calculator and therefore we have enough information to solve the problem. We will now enter the variables we have:

Begin by highlighting the field that corresponds to pressure altitude in ft.

Enter the 7620 value.

Highlight the field that corresponds to the calibrated airspeed in knots.

Enter the 195 value.

Now highlight the field that corresponds to the true air temperature in ^oC.

Enter the 4.6 value.

The remaining field is true airspeed. Press "Eval" and read the answer 220 knots on (a).

You also get other information in correlated variables that was calculated form the data .


Calculating Presure Altitude

Supposing you did not have the pressure altitude in the previous problem, you could calculate it from the calibrated altitude and altimeter setting using the pressure altitude calculator.
Highlight the field that corresponds to the calibrated altitude in ft.

Enter 8000.

Now highlight the field that corresponds to the altimeter setting in inHg.

Type in the 30.33 value.

The remaining field is pressure altitude. Press "Eval" and read the answer 7624 ft on (b). Notice the slight difference between 7620 (used on example 1) and 7624. This is a rounding error from entering the altimeter setting of 30.33 inHg. For the result to be exactly 7620 we would need an additional decimal digit on the altimeter setting.