What is the maximum combined time for the normal takeoff ITT limits of 965 Degrees C and 949 Degrees C?

To determine the maximum combined time for the normal takeoff ITT (Interstage Turbine Temperature) limits of 965 degrees Celsius and 949 degrees Celsius, one must refer to the operational limits set for aircraft engines. These limits define how long an engine can safely operate at elevated temperatures during takeoff conditions.

The established maximum combined time at which the ITT can reach these specified temperatures without risking engine damage or failure is indeed 5 minutes. This limit is based on engine performance data, testing, and manufacturer guidelines that ensure safety and efficiency during critical phases of flight, such as takeoff.

Each of the temperature limits represents a condition that can be tolerated for a specified duration. In the context of aircraft engines, exceeding the prescribed time at elevated temperatures can lead to premature wear or potential failure of engine components.

Thus, to adhere to safety regulations while allowing for optimal engine performance during takeoff, the maximum combined time of 5 minutes is the correct answer, aligning with standard operational procedures for managing engine limits during critical flight phases.