For what maximum duration should the maximum ITT remain during a start attempt?

The maximum duration that ITT (Interstage Turbine Temperature) should remain at its maximum level during a start attempt is indeed 5 seconds. This time limit is crucial for maintaining engine integrity and reliability during the starting process.

If the temperature exceeds the maximum allowable limit for too long, it can lead to engine damage or reduced lifespan. The T-6 has specific thermal limits to ensure safe operation and longevity of its components. Therefore, adherence to this limit of 5 seconds helps prevent excessive thermal stress and potential failure of the turbine materials.

Each of the other durations listed may not adequately protect the engine from overheating during start attempts, which is why they are not the correct answer. It's essential to follow these operational limits closely to ensure the safety and effectiveness of engine operations in the T-6 aircraft.