What is the minimum oil temperature required for engine start on the ground?

The minimum oil temperature required for engine start on the ground is critical to ensuring proper lubrication and reducing wear on engine components. For many aircraft, including the CRJ550, the minimum oil temperature for safe engine starting is typically established to avoid the risk of oil thickening. Oil that is too cold may not circulate properly, leading to inadequate lubrication when the engine is first started.

In this case, the correct answer states that the minimum temperature is -40 degrees C. This indicates that at temperatures as low as -40 degrees C, the oil is still considered efficacious enough to allow for a safe engine start. The design of the oil system accounts for cold start conditions, and for many aircraft engines, this is a standard operational limit.

By specifying this temperature, the manufacturer ensures that pilots and maintenance personnel can understand and adhere to the environmental limits for engine operations, which helps in preventing potential engine damage during start-up conditions.