What condition must the ITT meet prior to engine start?

The condition that the Interstage Turbine Temperature (ITT) must meet prior to engine start is that it should be below 150 degrees C. This requirement is critical to ensure that the engine starts safely and effectively, preventing potential damage that could be caused by starting an engine at elevated temperatures. If the ITT is above this threshold, it indicates that the engine components are too hot, which can lead to excessively high stresses being placed on the engine during the start sequence. Maintaining the ITT below the specified limit helps ensure a proper and safe engine start, minimizing the risk of issues related to thermal expansion and other heat-related concerns.