What temperature must the airplane be cold soaked at for more than 8 hours to require engine motoring?

The correct answer is based on the operational guidelines for the CRJ 200, which dictate procedures for starting engines after exposure to low temperatures. When the airplane has been cold-soaked at -30°C for more than 8 hours, it can lead to the possibility of fuel slushing in the fuel lines and potential challenges with engine start due to the low viscosity of the oil.

This cold-soaking condition necessitates motoring the engines to verify oil pressure and facilitate fuel flow before attempting to start in order to ensure a safe and reliable engine start. This procedure is important for maintaining engine performance and preventing damage caused by improperly prepared low-temperature starts.

By contrast, temperatures above -30°C do not generally require the same precautions, as the risk of issues during start-up diminishes with higher ambient temperatures. Thus, anything warmer would not fall under the same requirement for engine motoring.