Piper SENECA III - Page 180

SECTION 7
PIPER
AIRCRAFT
CORPORATION
DESCRIPTION
&
OPERATION
PA-34-220T,
SENECA III
The
feathering
governors
are
designed
to operate
in
the
conventional
manner
in
addition
to
their
accumulator
unfeathering capability.
The
accumulators
store
engine oil under
pressure
from
the
governors
which
is
released
back
to
the
governors
for propeller
unfeathering
when
the
propeller
control
lever
is
unlatched and
moved
forward from
the
feathered
position.
The
feathering
latches
hold
the
propeller
control
lever
in
the
feathered
position
and
prevent
inadvertent
unfeathering.
These
latches
must
be
manually
released
(pushed
forward)
to
unfeather
the propeller but do
not
change
the
feathering
procedure.
With
this
system
installed
the
feathering
time
is
10
-
17
seconds
and
unfeathering
times
is 8
-
12
seconds
depending
on
the
oil
temperature.
A
feathering
lock,
operated by
centrifugal
force,
prevents
feathering
during
engine shut
down
by
making
it impossible
to
feather
any
time the
engine
speed
falls
below
800
RPM. For this
reason,
when
airborne,
and the
pilot
wishes
to
feather
a
propeller
to
save
an
engine,
he
must
be
sure
to
move
the
propeller
control
into
the
"FEATHER" position,
REPORT:
VB-Il10
ISSUED:
JANUARY
8,
1981
7-6
REVISED:
APRIL 9, 1982