What is the maximum ITT for a windmill start?

What is the maximum ITT for a windmill start?

• A. 927C
• B. 1000C
• C. 850C
• D. 910C

Answer: (A)

The main idea is that ITT, or turbine inlet temperature, must stay within a safe limit during a windmill start. When the engine is being turned by external air, there’s limited cooling and the turbine components heat up as the compressor and turbine spool up. If the ITT climbs too high before ignition stabilizes the start, those blades and hot sections can suffer thermal stress or damage. Therefore the engine has a published maximum ITT for windmill starts to protect it. For this procedure, the specified maximum ITT during a windmill start is 927 C. Hitting or approaching that value means you should abort or modify the start to prevent exceeding the limit. The other temperatures listed aren’t the windmill-start limit for this engine setup; they might pertain to other phases or conditions, but they’re not the value used for windmill starts here.

The main idea is that ITT, or turbine inlet temperature, must stay within a safe limit during a windmill start. When the engine is being turned by external air, there’s limited cooling and the turbine components heat up as the compressor and turbine spool up. If the ITT climbs too high before ignition stabilizes the start, those blades and hot sections can suffer thermal stress or damage. Therefore the engine has a published maximum ITT for windmill starts to protect it.

For this procedure, the specified maximum ITT during a windmill start is 927 C. Hitting or approaching that value means you should abort or modify the start to prevent exceeding the limit. The other temperatures listed aren’t the windmill-start limit for this engine setup; they might pertain to other phases or conditions, but they’re not the value used for windmill starts here.