ITT must be ______ before attempting to ground start engine?

ITT must be ______ before attempting to ground start engine?

• A. Below 120C
• B. Below 150C
• C. Below 100C
• D. Below 90C

Answer: (A)

Inter-Turbine Temperature (ITT) is the temperature the engine core reaches just before fuel is ignited during a start. For a ground start, the engine must be cool enough that starting won’t push core temperatures beyond safe limits during the ignition surge. Keeping ITT below 120C provides a safe margin so the starter and turbine blades aren’t subjected to excessive thermal stress as the fuel is introduced and ignition occurs. If the ITT were allowed to be higher, starting could overload the engine’s thermal limits and risk damage or a failed start. The other options would either miss the necessary safety margin or impose unnecessary delay, whereas 120C is the established threshold for a safe ground start.

Inter-Turbine Temperature (ITT) is the temperature the engine core reaches just before fuel is ignited during a start. For a ground start, the engine must be cool enough that starting won’t push core temperatures beyond safe limits during the ignition surge. Keeping ITT below 120C provides a safe margin so the starter and turbine blades aren’t subjected to excessive thermal stress as the fuel is introduced and ignition occurs. If the ITT were allowed to be higher, starting could overload the engine’s thermal limits and risk damage or a failed start. The other options would either miss the necessary safety margin or impose unnecessary delay, whereas 120C is the established threshold for a safe ground start.