What is the first indication of a successful start of a turbine engine?

The rise in Exhaust Gas Temperature (EGT) is typically the first indication of a successful start of a turbine engine. When the engine starts, fuel is ignited in the combustion chamber, resulting in a rapid increase in temperature as the gases expand and are expelled. This rise in temperature is critical for confirming that combustion has initiated successfully, thus indicating that the engine has started.

Other indicators may follow, such as an increase in oil pressure, which generally occurs once the engine has stabilized and the oil system begins to function normally after startup. Additionally, fuel flow typically increases to establish a stable running condition, but this occurs alongside the rise in EGT rather than preceding it. A decrease in temperature would not be indicative of a successful start, as a functioning engine would produce heat rather than show a drop in temperature. Therefore, monitoring the rise in EGT is essential in the startup sequence to ensure that the engine is operating correctly.