Most light-aircraft engines are air-cooled — no liquid coolant; ram air through cooling fins on the cylinder head.
Air cooling components
| Component | Function |
|---|---|
| Cooling fins | Increase cylinder-head surface area for heat dissipation |
| Baffles | Direct ram-air through the fins rather than around them |
| Cowl flaps (some types) | Pilot-controlled flaps on the cowling — open to increase cooling airflow (climb, high power), close to reduce drag (cruise, descent) |
Key temperatures
| Instrument | German | Limit | Management |
|---|---|---|---|
| CHT | Zylinderkopftemperatur | Type-specific (e.g. Lycoming O-320: 260 °C max, cruise ≤ 200 °C) | Reduce power, enrich mixture, open cowl flaps |
| Oil temperature | Öltemperatur | Type-specific (e.g. Lycoming O-320: 245 °F = 118 °C max) | Reduce power; shallower climb |
Operational notes
- Don't go to high power too early — engine must warm up (oil temperature in the green).
- Sustained climb: shallow the climb if CHT approaches the upper limit.
- Shock cooling — avoid: during power-off descent CHT drops too fast, can crack cylinder.
- Recommendation: descend with some power (e.g. 1500 RPM rather than idle).
- Before full-power go-around: warm the engine slowly.