SUMMARY OF NOTABLE POINTS
• Icing forms stealthily
• Some aircraft/engine combinations are more susceptible than others
• Icing may occur in warm humid conditions and is a possibility at any time of the year in the UK
• MOGAS makes carb icing more likely
• Low power settings, such as in a descent or in the circuit, are more likely to produce carb icing
• Warming up the engine before take-off improves the effectiveness of any carb body heat
• Use full carb hot air frequently when flying in conditions where carb icing is likely. Remember the RPM gauge is the primary indication for a fixed pitch propeller; manifold pressure for variable pitch
• Treat the carb hot air as an ON/OFF control – either full hot or full cold
• It takes time for the heat to work and the engine may run roughly while ice is clearing
• Timely use of appropriate procedures can PREVENT THIS PROBLEM
· In the event of carb heat system failure in flight:
• Avoid likely carb icing conditions.
• Maintain high throttle settings – full throttle if possible.
• Weaken the mixture slightly.
• Land as soon as reasonably possible.