What method is used on turbine powered aircraft to determine when the condition of the fuel is approaching the danger of forming ice crystals?

In turbine-powered aircraft, monitoring the condition of the fuel is crucial, particularly to prevent the formation of ice crystals, which can lead to blockages in the fuel system and affect engine performance. The fuel temperature indicator plays a vital role in this process.

As the temperature of the fuel decreases, the risk of ice crystal formation increases. The fuel temperature indicator monitors the temperature of the fuel as it moves through the system, allowing pilots and maintenance personnel to be aware of temperature trends and take necessary actions if temperatures approach critical levels that could lead to ice crystal formation. By utilizing this indicator, operators can ensure that the fuel remains within safe temperature limits, thus preventing operational issues related to ice contamination.

While other instruments like fuel pressure gauges and fuel flow meters provide important information about the fuel system's performance, they do not directly indicate temperature changes that could lead to ice formation. The ice crystal detection sensor is also relevant, but it typically serves a more specific role in detecting existing ice crystals rather than monitoring temperature trends in fuel. Hence, the fuel temperature indicator is the most effective method for determining when the fuel conditions are approaching the danger of ice crystallization.