Propeller Owner’s Manual
139
DESCRIPTION AND OPERATION
61-00-39
Page 2-35
Rev. 17 Apr/20
Synchronizer/Synchrophaser Governor
Figure 2-14
(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 2-14 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.
APS6153
Speeder Spring
Flyweights
Pilot Valve
Coil
Rod
Pilot Control
