Print version: Check the carb icing graph [PDF 1.5 MB]

Issued 2015

A recent investigation into a Robinson R22 loss of power accident that revealed no mechanical abnormalities or fuel problems highlighted the potential for the undetected build-up of carburettor icing.

In a piston helicopter the combination of the governor attempting to maintain RPM and the freewheeling clutch can result in sudden loss of power, with associated loss of Rotor RPM, before any build-up of ice is noticed.

Pilots are reminded that carburettor icing can and does occur in environmental conditions that can appear benign, especially in summer months. In New Zealand’s maritime climate, conditions will very frequently be conducive to carburettor icing, whatever the time of year.

If actual temperature and dew point figures are not available then pilots should consider a conservative approach, and ensure they operate in full compliance with the manufacturer’s instructions for icing conditions.

For more information, download the ATSB carburettor icing resource:

The ongoing danger of carburettor icing(external link)

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