Recognise and Treat Carburettor Icing
Carb icing can occur from about -10°C to +25°C in humid conditions; check for it in SCADIE checks and apply full carb heat, expecting rough running until the ice clears.
1 min readKapiti Aero Club safety team
Weather in the Paraparaumu region is often conducive to carburettor icing, and members and instructors have reported it on multiple occasions. Here's a refresher on recognising, preventing and treating it.
- Carburettor icing can occur across a wide temperature range – approximately -10°C to +25°C – especially when relative humidity is high.
- Regular SCADIE checks every 15 minutes, which include cycling the carb heat, can tell us whether carb ice is forming.
- Symptoms: decreasing RPM, rough running or complete engine failure.
If carb icing is suspected, apply full carb heat. Expect rough running to continue for a short time, as the ice won't melt immediately – and as it melts, the water is drawn into the engine, which also causes rough running.
Key point: carb heat is not an immediate fix. It takes time for the ice to melt, and the engine will run rough until the ice is completely clear.