What is the maximum climb ITT?

• A. 825
• B. 820
• C. 850
• D. 800

Answer: (A)

Inter-Turbine Temperature is the temperature measured between the engine’s turbines and is a primary limit used to protect the turbine sections from overheating. The engine has different ITT limits for different phases of flight: a lower continuous limit for steady operation, a higher limit for takeoff, and an intermediate limit used for climb. During a climb, the engine is asked to develop more power than in cruise, but not at full takeoff power, so the ITT limit is set to allow that extra power while still safeguarding the turbines. For the PC-12 NGX, the climb ITT limit is 825°C, which is higher than the continuous limit but lower than the takeoff limit reserved for short-duration use. That’s why 825°C is the maximum climb ITT. The other values correspond to either the continuous limit or envelopes not applicable to sustained climb, so they aren’t the correct climb limit.