b.  
‘Intermittent Maximum Icing’. The intermittent maximum intensity of atmospheric icing conditions (intermittent maximum icing) is defined by the variables of the cloud liquid water content, the mean effective diameter of the cloud droplets, the ambient air temperature, and the inter-relationship of these three variables as shown in Fig. 5. The limiting icing envelope in terms of altitude and temperature is given in Fig. 6. The inter-relationship of cloud liquid water content with droplet diameter and altitude is determined from Fig. 5 and Fig. 6. The cloud liquid water content for intermittent maximum icing conditions of a horizontal extent, other than 2.6 n miles, is determined by the value of cloud liquid water content of Fig. 5 multiplied by the appropriate factor in Fig. 7 .

*‘IFR conditions’ means weather conditions below the minimum for flight under visual flight rules.
*‘Indicated airspeed’ means the speed of an aircraft as shown on its pitot static airspeed indicator calibrated to reflect standard atmosphere adiabatic compressible flow at sea level uncorrected for airspeed system errors.
*‘Instrument’ means a device using an internal mechanism to show visually or aurally the attitude, altitude, or operation of an aircraft or aircraft part. It includes electronic devices for automatically controlling an aircraft in flight.