Outside Air Temperature

Outside Air Temperature measurement is an important parameter for pilots because the temperature affects the Aircraft’s Performance. In our earlier lesson we had seen the various Types of Flight or Aircraft Instruments.


Variation in air density due to change in Outside Air Temperature affects the Airframe as well as the Engine’s Performance. This inturn affects many other factors like Climb Gradent, Take-off Run Required, Landing-Run Required and many more such parameters.

In addition, measurement of Outside Air Temperature affects the measurement of aircraft parameters like the Speed or Altitude of aircraft. Aircraft Icing is quite hazardous to Flight Safety since it leads to a decrease in lift and an increase in weight as well as drag. Temperature Measurement is also required to detect and avoid Icing Conditions.

Aircraft Icing may also lead to freezing and loss of controls in addition to reduction in power of the engine. In extreme circumstances, icing may lead to engine flame out or even damage to aircraft’s airframe. Accurate measurement of OAT is essential to detect potential Icing Conditions enabling the pilot to take pro-active measures for Icing Prevention.

In this lesson, we have seen the importance of Outside Air Temperature measurement, In our next post, we shall discuss the various common Units of Temperature Measurement and the realtionship between them.