Propeller Owner's Manual
136
DESCRIPTION AND OPERATION
61-00-36
Page 2-27
Rev. 2 Feb/17
B. Propeller De-ice System
A propeller de-ice system is a system that permits ice to
form, and then removes it by electrically heating the de-ice
boots. The ice partially melts and is thrown from the blade by
centrifugal force.
(1) System Overview
(a) A de-ice system consists of one or more on/off
switches, a timer or cycling unit, a slip ring, brush
blocks, and de-ice boots. The pilot controls the
operation of the de-ice system by turning on one or
more switches. All de-ice systems have a master
switch, and may have another toggle switch for each
propeller. Some systems also have a selector switch
to adjust for light or heavy icing conditions.
(b) The timer or cycling unit determines the sequence of
which blades (or portion thereof) are currently being
de-iced, and for what length of time. The cycling unit
applies power to each de-ice boot or boot segment in
a sequential order.
(c) A brush block, which is normally mounted on the
engine just behind the propeller, is used to transfer
electricity to the slip ring. The slip ring rotates with
the propeller, and provides a current path to the blade
de-ice boots.
(d) De-ice boots contain internal heating elements. These
boots are securely attached to the leading edges of
each blade with adhesive.
