What is the ITT ground start limit?

• A. 815
• B. 700
• C. 900
• D. 1000

Answer: (A)

Inter-Turbine Temperature (ITT) is the temperature the engine experiences in the turbine area, and it’s a critical measure used to protect the engine during starts and operation. On a ground start, fuel is introduced and the engine spools up, causing ITT to rise quickly. If ITT climbs too high, thermal stress can damage turbine blades, bearings, and other components. To prevent that, manufacturers set a specific limit for starts on the ground that’s lower than the limit used during takeoff or steady operation. This limit creates a safe margin for the warm-up phase while still allowing a normal start sequence. The value commonly used for the ground-start limit is 815 degrees Celsius, which is why that option is the correct one. Higher values like 900 or 1000 are typically associated with takeoff or continuous operation, not the start phase, and 700 would be too restrictive for many engines, risking aborted starts.