Before attempting an air start, ITT must be below what value?

Before attempting an air start, ITT must be below what value?

• A. 90C
• B. 70C
• C. 100C
• D. 110C

Answer: (A)

ITT, or Inter-Turbine Temperature, is a measure of how hot the turbine section is when starting. Before using external air to start the engine, the ITT must be below 90C to prevent a hot start. If ITT is higher, introducing fuel for the start could push the turbine temperature into an unsafe range, risking damage to the engine. The 90C threshold gives a safe margin for the start sequence. Values higher than that would be unsafe for an air start, while a much lower value would be unnecessarily restrictive for normal operations.

ITT, or Inter-Turbine Temperature, is a measure of how hot the turbine section is when starting. Before using external air to start the engine, the ITT must be below 90C to prevent a hot start. If ITT is higher, introducing fuel for the start could push the turbine temperature into an unsafe range, risking damage to the engine. The 90C threshold gives a safe margin for the start sequence. Values higher than that would be unsafe for an air start, while a much lower value would be unnecessarily restrictive for normal operations.