Refer to figure.

To calculate the TAS from a given CAS with the flight computer, we must calculate the pressure altitude (altitude based on standard pressure setting). Changing the altimeter setting from a QNH of 1046 hPa to a lower pressure setting (1013 hPa), the reading will decrease:

• PA = 3000 ft - (1046 - 1013) hPa x 30 ft/hPa
• PA = 3000 ft - 33 x 30 ft = 3000 ft - 990 ft = 2010 ft

Now, using the Flight Computer:

Align the pressure altitude window (2 010 ft) with the OAT (+10ºC);

Once the wheel is aligned, find the CAS of 154 kts on the inner most scale. You should then be able to read the TAS of 158 kts on the outer scale.