Propeller Owner’s Manual
147
DESCRIPTION AND OPERATION
61-00-47
Page 2-31
Rev. 16 May/20
APS6153
Synchronizer/Synchrophaser Governor
Figure 2-16
Speeder Spring
Flyweights
Pilot Valve
Coil
Rod
Pilot Control
(6) A synchronizing system can be employed in a multi-
engine aircraft to keep the engines operating at the
same RPM. A synchrophasing system not only keeps
the RPM of the engines consistent, but also keeps
the propeller blades in phase with each other. Both
synchronizing and synchrophasing systems serve
to reduce noise and vibration. Figure 2-16 illustrates
a governor as a component of a synchronizing or
synchrophasing system.
(a) Hartzell Propeller Inc. synchronizing or
synchrophasing systems use one engine (the master
engine) as an RPM and phase reference and adjust
the RPM of the remaining engine(s) [slave engine(s)]
to match it. The RPM of the master engine is
monitored electronically, and this information is
used to adjust the voltage applied to the electrical
coil on the slave governor(s). The voltage to the
coil either raises or lowers a rod which changes the
force of the speeder spring. In this manner, engine
RPM and phase of the propellers is synchronized or
synchrophased.
