Piper SENECA III - Engines

SECTION
7
PIPER
AIRCRAFT
CORPORATION
DESCRIPTION &
OPERATION
PA-34-220T, SENECA
IH
entry.
Each
wing
contains
two
fuel
tanks
as
standard equipment.
An
optional
third
tank
may
be
installed
on
each
side.
The
tanks
on one
side
are
filled
through
a
single
filler
neck
located
well
outboard
of
the
engine nacelle.
A
vertical
stabilizer,
an
all-movable
horizontal
stabilator,
and
a
rudder
make
up
the
empennage.
The
stabilator
incorporates
an
anti-servo
tab
which
improves
longitudinal
stability and
provides
longitudinal trim.
This
tab
moves
in
the
same
direction
as
the
stabilator,
but
with
increased
travel.
Rudder
effectiveness
is
increased by
an
anti-servo
tab
on
the rudder.
7.5
ENGINES
The
Seneca
Ill
is
powered by
two
Teledyne
Continental
six-cylinder
turbocharged
engines each
rated
at
200 horsepower
at
2600 R
PM maximum
continuous
at
sea
level
and
220 horsepower
at
2800 RPM
takeoff
power
for
five
minutes. The
engines
are
air
cooled
and
fuel injected
and
are
equipped
with
oil
coolers
with
low
temperature
bypass
systems
and
engine
mounted
oil
filters. A
winterization
plate
is
provided
to
restrict
air
during winter
operation.
(See
Winterization
in Handling
and
Servicing
Section.)
Asym-
metric
thrust
during
takeoff
and
climb is
eliminated
by thecounter-rotation
of
the
engines,
the
left engine
rotating
in
a
clockwise
direction
when
viewed
from the
cockpit,
and the
right
engine
rotating
counterclockwise.
The
engines
are
accessible
through removable
panels,
one on
either side
of
each
engine
cowling.
Engine
mounts
are
constructed
of
steel
tubing,
and
dynafocal
engine
mounts
are
provided
to
reduce
vibration.
A
Ray-Jay
turbocharger
on
each
engine is operated by
exhaust
gases.
Exhaust
gases
rotate
a
turbine wheel, which
in
turn
drives
an
air
compressor,
Induction
air
is
compressed
(supercharged)
and
distributed into
the
engine
air
manifold, and the
exhaust
gases
which
drive
the
compressor are
dis-
charged
overboard.
Engine
induction
air
is
taken
from
withinthecowling,is
filtered,
and
is then
directed into the turbocharger
compressor
inlet.
Each
engine cylinder is
supplied
with pressurized
air
in
operation
from
sea
level
to
maximum
operating
altitude.
The
pressure
relief valve
protects
the
engine
from
inadvertently
exceeding
42 inches Hg; 40
inches Hg is
manually
set
with
the
throttles.
The turbo bypass
orifice
is
preset
for
40 inches
Hg
at
12,000
feet
densíty
altitude
at
full throttle
and
2600
RPM.
REPORT:
VB-1110
ISSUED:
JANUARY
8,
1981
7-2