Definition
The ratio of fuel to air being delivered to the engine's cylinders for combustion, controlled by the pilot via the mixture control in the cockpit. The mixture can be made richer (more fuel relative to air) or leaner (less fuel relative to air), and pulling the control fully out cuts off fuel entirely to shut down the engine.
Plain English
How much fuel is being mixed with the air going into the engine. The pilot can adjust this with a knob or lever in the cockpit to add more fuel, less fuel, or shut the fuel off completely.
Context Anchor
Seen in engine operation, after-landing, and shutdown procedures, especially when the checklist calls for moving the mixture to idle cutoff.
Derivation
Mixture comes from the Latin idea of “mixing.” That helps here because the engine is not using fuel alone; it needs fuel mixed with air in the right amount to run properly.
Why Pilots Care
Correct mixture settings prevent engine damage, roughness, or failure while improving fuel economy and power.
Grounding Statement
Picture the engine needing both air and fuel together; the mixture is the balance between those two.
Intuition Check
Do not read mixture as just any random combination. In this cockpit context, it means the specific fuel-and-air blend for the engine, and often the control used to adjust that blend.
Example Sentence 1
After leveling off in cruise, the pilot leaned the mixture until the engine ran smoothly at the target fuel flow.
Example Sentence 2
Before engine shutdown the pilot pulled the mixture control to the idle-cutoff position.