The minimum oil temperature for starting is:

• A. -20 degrees C
• B. -40 degrees C
• C. 0 degrees C
• D. -60 degrees C

Answer: (B)

Oil temperature directly affects lubrication at startup. When oil is very cold, its viscosity is high, so it resists flow, increases engine friction, and makes it harder for oil to reach bearings and form a protective film right as the engine starts. That extra resistance can overload the starter and reduce the likelihood of a clean, safe start.

Beechjet 400A specifies a minimum oil temperature for starting at -40 C. This boundary ensures the oil is thin enough to circulate quickly and establish proper lubrication as the engine comes up to speed. If the oil is colder than -40 C, starting is not advised because the risk of insufficient lubrication and potential damage is higher. If the oil is warmer than -40 C, start is permissible because lubrication will be adequate.

So, the threshold value is -40 C, with starting allowed at -40 C or warmer and not allowed below that.