AIRPLANE
OPERATIONS
MANUAL
GROUND SERVICING
REVISION 38
1-12-20
Page
3
Code
01
AOM-145/1114
A deicing fluid may be pure heated water, or a mixture of heated water
and type I, II, III or IV fluids. Heating is applied to a minimum
temperature of 60°C to assure maximum deicing efficiency.
Anti-icing fluids include types I, II, III or IV fluids in a mixture with water
or undiluted.
Type I fluid is diluted with water to result in a freezing point
approximately 10°C below ambient temperature. No additional
holdover time is obtained by increasing the concentration of this fluid
in the fluid/water mixture. However, increasing the concentration of
fluids II, III and IV in a fluid/water mixture results in an additional
holdover time.
The holdover time of the type IV fluid is greater than that of type II,
which in its turn has a longer holdover time than type III fluid.
Type I fluid is normally pink or reddish orange in color, type II fluid is
normally straw-colored, type III is bright yellow and type IV is green.
Type IV is an enhanced-performance fluid and offers significant
operational advantages in terms of holdover times. However,
thickened fluids may dry out during flight and residues may
accumulate in aerodynamically quiet areas. The residues may turn to
a gel which can freeze in flight, potentially restricting the movement of
flight controls. Operators are reminded to frequently inspect control
surfaces, gaps and tab hinges for signs of residual gel. If an approved
fluid during actual use shows gelling, poor water wash off or unusual
dry-out, EMBRAER should be notified.
THE USE OF HOLDOVER TIMES
Holdover times for the fluids are derived for each specific fluid brand,
under various temperatures, fluid concentration and precipitation
category. Note that the lower limit of the published holdover time is
used to indicate the estimated time of protection during moderate
precipitation, and the upper limit indicates the estimated time during
light precipitation. Heavy conditions are not covered. Therefore, crew
experience and airline orientation is required to clearly settle what is
heavy, moderate or light. It is very important to determine the
appropriate holdover time for the prevailing environmental conditions,
and apply them on the line.
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