Which ITT reading is associated with fuel introduction?

The correct choice indicates that an ITT (Interstage Turbine Temperature) reading of 150ºC is associated with the introduction of fuel in the aircraft's engine operation. This temperature is significant because it often reflects the point in the start sequence for turbine engines where fuel is introduced into the combustion chamber.

At around 150ºC, the engine is typically at a temperature that allows for safe and efficient combustion. Introducing fuel at this stage helps ensure optimal fuel-air mixture and prevents combustion instability, which can lead to undesirable engine performance or even damage if introduced at an inappropriate temperature.

Higher ITT readings, such as those indicated in the other options, are generally associated with stable, steady-state operations of the engine, when it is achieving its maximum performance. Therefore, fuel introduction at significantly higher temperatures would not align with safe operational practices.