Why do turbine-engine aircraft have fuel temperature indicating systems?

Turbine-engine aircraft are equipped with fuel temperature indicating systems primarily to prevent ice crystal formation in the fuel. At low temperatures, particularly at high altitudes, the fuel can become cold enough for ice crystals to form. These ice crystals can clog fuel lines and filters, which may lead to fuel starvation for the engine. By monitoring fuel temperature, pilots can take appropriate actions, such as adjusting altitude or making fuel management decisions to ensure that the fuel remains free of ice contamination, thus maintaining a safe and reliable operation of the aircraft.

Though other options mention aspects related to efficiency, performance, and fuel consumption, they do not directly address the critical safety concerns associated with fuel temperature in turbine engines. Ice formation poses a significant risk, and the monitoring system is ultimately centered around ensuring the integrity and flow of fuel to the engines.