Definition
The procedure of turning over a reciprocating aircraft engine with the starter, without ignition, to circulate oil through the engine before a normal start. This is done when the engine has been sitting unused long enough for oil to drain out of the upper cylinders, bearings, and oil passages.
Plain English
Spinning the engine with the starter — but without letting it actually start — so that oil gets pumped around inside before the engine fires up and begins running under load.
Context Anchor
Used in piston-engine starting procedures, especially during the first start of the day or after the aircraft has been sitting long enough for the engine to cool.
Derivation
‘Crank’ comes from the old practice of hand-cranking early engines to start them. The word survived into modern usage to mean ‘turn the engine over with the starter.’ ‘Cold engine’ simply means an engine that has not been recently run, so its parts and oil are at ambient temperature.
Why Pilots Care
Correct cold-engine starting technique prevents wear, hydraulic lock, and failed starts that can strand the aircraft.
Intuition Check
Cold does not only mean freezing weather here. It means the engine itself is not warmed up to normal operating temperature.
Example Sentence 1
After the aircraft sat in the hangar for two months, the mechanic cranked the cold engine with the ignition off before attempting a normal start.
Example Sentence 2
After a long shutdown the mechanic advised waiting a minute before attempting to crank the cold engine.