Engine cooling & throttle handling
Type: most small aircraft air cooled; some liquid cooled (TP 1102 l.842).
Airflow path (PHAK ch.7):
- Air enters openings in front of cowling.
- Baffles route air over fins on cylinders.
- Hot air exits openings in lower aft cowling.
Split: oil cools internal parts; air cools external surface.
| Condition | Cooling effect | Handling | Cite |
|---|---|---|---|
| Ground, takeoff, go-around, other high-power low-airspeed periods | Air cooling least effective | TP 1102 l.842 | |
| High-speed descent | Excess air; can shock-cool engine | PHAK ch.7 | |
| Low or idle power (e.g. low-power descent), even in warm weather | Engine cools rapidly | Sudden power burst (e.g. overshoot) can damage cold engine or cause momentary malfunction | TP 1102 l.874 |
| Sustained descent | Cold cylinders foul spark plugs; so does prolonged idling | Apply power periodically (cruise power a few seconds at intervals) to keep temperatures near normal | TP 1102 l.4673 |
Throttle: move promptly but smoothly, either direction; avoids backfiring and abrupt power loss. A hard, fast push risks both.
Shutdown:
| After | Do |
|---|---|
| Normal approach, landing, taxi | Shut down straight away, no extra idling |
| Excessive power while taxiing | Idle 2 to 3 minutes at just above idling speed first |
Trap: treating high-speed descents as the hard case for cooling; the weak case is high power at low airspeed.
References
- PHAK ch.7
- TP 1102 l.806, l.842, l.874 (Flight Training Manual, engine cooling)
- TP 1102 (Aeroplane Flight Training Manual), ch.3 Engine Handling: General