Hartzell HC-D2MV20-3 Series, Owner'S Manual And Logbook, Page: 43 / 204

Propeller Owner's Manual
140
DESCRIPTION AND OPERATION
61-00-40
Page 2-3
Nov/02
1. Description of Propeller and Systems
A. General Description (Construction)
(1) The propellers covered in this manual are capable of either
constant speed operation or attain a blade angle through
manual selection by the pilot while in flight. All of these
propellers use aluminum blades and are intended for use
with reciprocating engines.
(2) The Hartzell Hydro-Selective propeller changes blade pitch
through hydraulic actuation that is controlled manually.
Manual control allows the pilot to select a blade angle by
moving a cockpit control to result in a desired RPM setting.
Governed control uses a device called a governor to sense
engine RPM and will change blade angle as necessary to
maintain the RPM selected by the pilot. Governed control is
referred to as constant speed operation.
(3) Blade angles range from a low positive blade angle to a
high positive blade angle or from a high positive blade
angle to a reverse blade angle. Feathering is not possible
with these propellers.
(4) The Hartzell Hydro-Selective propeller that uses manual
control consists primarily of a propeller assembly, a
hydraulic unit, and a valve assembly. The constant speed
propeller that uses governor control has a governor, a
T-drive unit, and a hydraulic hose connecting the governor
and the hydraulic unit.