Propeller Owner’s Manual
139
DESCRIPTION AND OPERATION
61-00-39
Page 2-5
Rev. 17 Apr/20
1. Description of Propellers and Systems
A. Feathering Propellers HC-B(3,5)( )( )-2( )
Refer to Figure 2-1. The propellers described in this section
are constant speed, feathering, and non-reversing. They use
a single oil supply from a governing device to hydraulically
actuate a change in blade angle. The propellers can have
three or five blades, and they are used primarily on Pratt and
Whitney turbine engines.
Propeller blades and bearing assemblies are mounted on the
arms of a steel hub unit (Figure 2-2) and are held in place by
two-piece blade clamps. A cylinder is threaded onto the hub,
and a feathering spring assembly is installed in the cylinder.
A piston is placed over the cylinder and is connected by a
link arm to each blade clamp. Propeller blade angle change
is accomplished through the linear motion of the hydraulically
actuated piston that is transmitted to each blade through the
link arms and blade clamps.
Steel Hub Unit
Figure 2-2
APS2063
