If the bleed air temperature exceeds what value, will the yellow DUCT TEMP caution message illuminate?

The yellow DUCT TEMP caution message illuminates when the bleed air temperature exceeds 300°F. This is a critical safety feature designed to alert pilots of potential overheating in the bleed air ducts, which could indicate a malfunction or failure in the system. Monitoring duct temperature is essential for the safety and efficiency of engine operation and aircraft systems that rely on bleed air.

In terms of the other temperature values, 165°C and 300°C are above acceptable ranges for the T-6B system, and although the temperature reading in Fahrenheit is more common in aviation for this specific measurement, 165°F is not the correct threshold for triggering the caution message. Instead, the system is designed with the higher 300°F limit to provide a safeguard against risks associated with excess heat in the ducts.