Army Aircraft Icing
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ingestion. Note: Use/runoff should not be allowed to contact water sources. A
containment area should be utilized if possible.
b. Rapid oxidation and fire can occur when glycol solutions come in
contact with a short or components carrying direct current (DC).
c. Heated deice fluids will damage plastic windows, covers, boots,
bearings, and greases. Avoid all contact with these surfaces.
d. Do not allow isopropyl alcohol or other alcohol solutions to contact
acrylic canopies.
e. Do not spray alcohol-based fluid on magnesium components.
f. TM 55-1520-240-23-10 (U.S. Army 1982), paragraph 1-86, and
Chapter 10, Arctic Maintenance, address cold-weather operations beyond blade
deicing, to include covering openings, removal of snow and ice from inlets,
removal of bypass panels, freeing frozen compressor rotors, battery storage in
low temperatures, avoiding damage to seals and moving shafts from ice and dirt,
and ice removal from windshields. These procedures should be used in coordina-
tion with your specific aircraft instructions.
5. Summary of general options in order of preference
a. The (#1) preferred method for deicing aircraft is to avoid icing condi-
tions by storing MEDEVAC, attack, and other critical mission aircraft in hangars
or clam-shelter-type temporary facilities. When icing conditions are predicted,
temporary covers over blades may be used to prevent accumulation.
b. The (#2) preferred method for deicing aircraft stored outside where ice
has collected on them is to bring the aircraft inside a shelter or facility to thaw.
c. The (#3) preferred method for preventing ice buildup or deicing
aircraft is to use an available heat source to direct warm air near the blades.
Caution: This method poses risks to the aircraft components. Exposure to
extreme variations in temperature can crack windshields and cause debonding
problems with composite materials. Air should not be hot. Warm temperatures in
the appropriate range will feel warm to a bare hand, but not be uncomfortable to
a bare hand held in the airstream for extended periods of time. Commonly avail-
able sources of heat include "Herman Nelsons" used at a suitable distance from
the aircraft, or an aviation ground power unit (AGPU) using a mixture of exhaust
and fresh air.
d. The (#4) preferred method to deice aircraft is to avoid exposure to ice
by using portable covers. Caution: This method can cause damage from abrasion
produced by rubbing covers or tie-downs. Covers do not work well on damp or
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