RAZAIR
‐
A1
‐
METRO
‐
III
‐
AFM
‐
001
1
‐
23
OIL
SYSTEM
The
engine
oil
system
provides
for
cooling
and
lubrication
of
the
main
engine
bearings
and
the
reduction
gear.
In
addition
to
these
functions
the
engine
oil
system
supplies
oil
for
propeller
control,
negative
torque
sensing
(NTS)
and
the
unfeathering
pump.
If
oil
pressure
drops
below
40
PSI
the
appropriate
L
or
R
OIL
PRESSURE
warning
light
in
the
annunciator
panel
will
illuminate.
FUEL
SYSTEM
The
engine
fuel
system
provides
the
proper
amount
of
metered
fuel
to
the
combustion
chamber
under
the
three
phases
of
operation:
Starting
and
acceleration
to
idle,
Ground
operation,
and
Flight
operation
Fuel
Control
Unit
Power
(throttle)
lever
and
speed
(rpm)
lever
position
are
inputs
to
the
fuel
control
unit
and
affect
the
fuel
metered
to
the
engines.
The
fuel
control
unit
contains
an
underspeed
governor,
an
overspeed
governor
and
manual
control
of
fuel
metering.
The
underspeed
governor
operates
to
prevent
the
rpm
from
going
below
a
value
set
by
the
speed
lever.
If
engine
speed
should
decrease
below
the
selected
setting,
the
underspeed
governor
increases
the
fuel
flow
to
oppose
the
speed
decrease.
The
underspeed
governor
can
be
set
between
71
and
97%
rpm
by
the
speed
lever.
Manual
control
of
fuel
metering
by
the
power
lever
occurs
when
the
power
lever
is
moved
forward
of
FLT
IDLE
(10%
Throttle).
The
overspeed
governor
is
a
safety
device
to
prevent
excessive
engine
overspeed
in
the
event
of
propeller
malfunction.
Excess
engine
rpm
limits
fuel
metering
to
prevent
additional
rpm
increase.
Fuel
Solenoid
Valve
The
fuel
solenoid
valve
is
opened
by
the
start
system
and
closed
by
clicking
on
the
STOP
button.
It
can
also
be
closed
by
pulling
the
ENGINE
STOP
AND
FEATHER
control.
If
the
STOP
AND
FEATHER
control
is
pushed
in,
the
fuel
solenoid
valve
can
be
opened
by
the
START
button.