2-101. ANTI-ICING, DEICING, AND DEFROSTING TREATMENT.
Do not apply anti-icing, deicing, and defrosting luid to exposed aircraft surfaces if snow is expected.
Melting snow will dilute the defrosting luid and form a slush mixture which will freeze in place and
become dificult to remove.
The aircraft is protected in subfreezing weather by spraying the surfaces (to be covered with protective covers) with
defrosting luid. Spraying defrosting luid on aircraft surfaces before installing protective covers will permit protective
covers to be removed with a minimum of sticking. To prevent freezing rain and snow from blowing under protective
covers and diluting the luid, ensure that protective covers are itted tightly. As a deicing measure, keep exposed
aircraft surface wet with luid for protection against frost. Use undiluted anti-icing, deicing, and defrosting luid (MIL-
A-8243) to treat aircraft surfaces for protection against freezing rain and frost. Spray aircraft surface suficiently to
wet area but without excessive drainage. A ine spray is recommended to prevent waste. Use diluted, hot luid to
remove ice accumulations.
a. Remove frost or ice accumulations from aircraft surfaces by spraying with diluted anti-icing, deicing, and
b. Spray diluted hot luid in a solid stream (not over 15 gallons per minute). Thoroughly saturate aircraft surface
and remove loose ice. Keep a suficient quantity of diluted hot luid on aircraft surface coated with ice to prevent
liquid layer from freezing. Diluted hot luid should be sprayed at a high pressure, but not exceeding 300 PSI.
c. When facilities for heating are not available and it is deemed necessary to remove ice accumulations from
aircraft surfaces undiluted defrosting luid may be used. Spray undiluted defrosting luid at 15-minute intervals to
assure complete coverage. Removal of ice accumulations using undiluted defrosting luid is expensive and slow.
d. Use undiluted defrosting luid to melt ice around the tires if frozen to ground. Move aircraft as soon as tires
Recommended Fluid Dilution Chart
FREEZING POINT OF
FLUID BY VOLUME
30° and above
1. Use anti-icing and deicing luid (MIL-A-8243 or commercial luids).
2. Heat Mixture to a temperature of 82° to 93°C (180° to 200°F).