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Derive or compute TAS, given IAS, pressure altitude and air temperature in degrees Celsius.
To Find the TAS you will need the following:
- Pressure Altitude
- OAT (Outside Air Temperature)
- CAS or IAS
(Use CAS if it is available, otherwise use IAS)
Given CAS 110 knots, P.alt 18'000 feet, OAT 15ºC what is the TAS
Using airspeed window set temp against OAT
Find CAS on inner scale
Read off TAS opposite on outer scale
TAS 156 knots
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