Recurrent Made Easy Practice Test

The main idea is that fuel properties can degrade at very cold temperatures, so there’s a lower limit for safe takeoff based on bulk fuel temperature. If the bulk fuel temperature is below -30°C, takeoff is prohibited because the fuel can become too viscous, crystals or wax can form, and any free water can freeze, all of which can clog filters and fuel lines or disrupt engine fuel delivery during high-power operation. Keeping the bulk fuel temperature above -30°C ensures the fuel remains within a safe, workable range for the system.

So takeoff is permitted only when the bulk fuel temperature is above -30°C.