Before the first flight of a cold-soaked aircraft at -30C or below, what must be done to the engines?

The requirement to motor the engines for 60 seconds before the first flight of a cold-soaked aircraft at temperatures of -30 degrees Celsius or below is important for ensuring the engines operate safely and efficiently. Cold-soaking can result in oil thickening and fuel system issues, which can impede engine performance.

Motoring the engines allows for the lubrication system to circulate oil throughout the engine components, preventing the risk of engine damage due to inadequate lubrication. This process also helps to ensure that fuel flows correctly through the system and that the ignition components are functioning properly. While other procedures may seem relevant, motoring specifically addresses the need to prepare the engine by allowing for proper oil circulation before attempting a start, thus mitigating risks associated with cold ambient temperatures.

This practice is crucial for maintaining engine reliability and performance, especially after exposure to extreme cold, as it ensures that everything is in working order before takeoff.