Definition
The period after engine start during which the engine is run at a low to moderate RPM to allow oil to circulate and engine components to reach normal operating temperatures before higher power is applied. On airplanes equipped with a constant-speed propeller, the warm-up is conducted with the propeller control in the full-increase (high RPM, low pitch) position so that oil flows through the propeller hub and the governor is exercised before takeoff.
Plain English
Running the engine at a gentle power setting after start to let it heat up evenly and get the oil flowing properly, so it's ready to handle takeoff power without damage.
Context Anchor
You encounter this during engine start, before-takeoff checks, and constant-speed propeller checks, especially on cold days.
Why Pilots Care
Cold oil in the propeller hub and governor can cause sluggish response or damage if high loads are applied too soon.
Intuition Check
Warm-up does not mean waiting until the cockpit feels warm. In this context, it means following the airplane’s procedure until the engine and propeller system are ready for higher power.
Example Sentence 1
During warm-up, the pilot kept the propeller control full forward and watched the oil temperature rise into the normal operating range before taxiing.
Example Sentence 2
During the warm-up, the pilot advanced the throttle gradually while monitoring cylinder head temperature.