Hartzell HC-C2YR-4CF/FC8475-6, Руководство пользователя и журнал учета

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Propeller Owner's Manual
115N
DESCRIPTION AND OPERATION
61-00-15
Page 2-7
Rev. 24 Dec/20
C. Constant Speed, Feathering Propellers ( )HC-( )( )Y( )-2
(1) Refer to Figure 2-2. The -2 Series propellers are constant
speed propellers that use an air charge, spring, and
counterweights (if installed) to move the blades to high
pitch/feather position. Blade centrifugal twisting moment
acts to move the blades to low pitch, but the air charge,
spring, and counterweights overcome this force. Oil
pressure against a propeller mounted hydraulic piston
opposes the counterweight, spring, and air charge forces
to move the blades to low blade angle (low pitch).
(2) The action of the air charge, spring, and counterweights
tends to move the blades to a higher blade angle (high
pitch), reducing engine RPM. Oil pressure toward low
pitch increases engine RPM.
(3) If oil pressure is lost during operation, the propeller will
feather. Feathering occurs because the air charge, spring,
and blade counterweights are no longer opposed by
hydraulic oil pressure. The air charge, spring and blade
counterweights are then free to increase blade pitch to the
feathering (high pitch) stop.
(4) Normal in-flight feathering of these propellers is
accomplished when the pilot retards the propeller pitch
control past the feather detent. This allows control oil to
drain from the cylinder and return to the engine sump. The
engine can then be shut down.
(5) Normal in-flight unfeathering is accomplished when the
pilot positions the propeller pitch control into the normal
flight (governing) range and an engine restart is attempted.
(6) Some aircraft are equipped with a hydraulic accumulator,
which stores a supply of oil under pressure. This oil supply
is released to unfeather the propeller during an in-flight
engine restart. Pressurized oil is directed to the propeller,
resulting in blade angle decrease. The propeller begins to
windmill, and engine restart is possible.