Change 3 2-27
In this event, the appropriate # 1 or # 2 ICE VANE POW-
ER SELECT switch should be placed in the STBY posi-
tion. Once the vane is successfully positioned, using the
standby (STBY) system, the amber annunciator(s) will
extinguish and the applicable green #1 VANE EXT or #2
VANE EXT annunciator(s) will illuminate.
c. Engine Anti-Ice System.
(1) Air Inlet. A small duct, facing into the exhaust
flow in the engines left exhaust stack diverts a small
portion of the engine exhaust gases to the engine air inlet
lip. The gases are circulated through the engine air inlet
lip and then exhausted through a duct in the engines
right exhaust stack. The continuous flow of hot engine
exhaust gases heats the engine air inlet lip, preventing
the formation of ice. Two switches placarded ENG INLET
LIP HEAT #1 and #2 (located on the overhead control
panel, fig. 2-13), operate solenoid valves in the lip heat
exhaust plumbing. These valves control the flow of hot
exhaust gasses to the inlet air lip assemblies.
(2) Fuel Heater. An oil-to-fuel heat exchanger,
located in the engine accessory case, operates continu-
ously and automatically to heat the fuel sufficiently to
prevent ice from collecting in the fuel control unit.
2-21. ENGINE FUEL CONTROL SYSTEM.
a. Description. The basic engine fuel system consists
of an engine driven fuel pump, a fuel control unit, a fuel
flow divider, a dual fuel manifold, fourteen fuel nozzles
and a purge system. The fuel purge system forces resid-
ual fuel from the manifolds to the combustion chamber
where it is consumed.
b. Fuel Control Unit. One fuel control unit is mounted
on the accessory case of the engine. This unit is a hydro-
pneumatic metering device which determines the proper
fuel flow schedule for the engine to produce the amount
of power requested by the relative position of its POWER
lever. The control of developed engine power is accom-
plished by adjusting the engine gas generator (N1)
speed. N1 speed is controlled by varying the amount of
fuel injected into the combustion chamber through the
fuel nozzles. Engine shutdown is accomplished by mov-
ing the appropriate CONDITION lever to the full aft FUEL
CUTOFF position, which shuts off the fuel supply.
2-22. POWER LEVERS.
Moving the POWER levers below the flight idle
gate without the engines running may result in
damage to the reverse mechanism linkage.
The two POWER levers are located on the control
pedestal (fig. 2-12), and are placarded POWER. These
levers regulate power in the reverse, idle and forward
ranges, operating so that forward movement increases
engine power. Power control is accomplished through
adjustment of the N1 speed governor in the fuel control
unit. Power is increased when N1 RPM is increased. The
POWER levers also control propeller reverse pitch. Dis-
tinct movement (pulling up and then aft on the POWER
lever) by the pilot is required for operation in the ground
fine and reverse ranges. Forward lever travel range is
designated INCR (increase), supplemented by an arrow
pointing forward. Lever travel range is marked IDLE,
LIFT, GROUND FINE, LIFT, and REVERSE. A placard
below the lever slots reads: CAUTION - REVERSE
ONLY WITH ENGINES RUNNING.
2-23. CONDITION LEVERS.
The two CONDITION levers are located on the control
pedestal (fig. 2-12). Each lever starts and stops the fuel
supply, and controls the idle speed for its respective en-
gine. The levers have three placarded positions: FUEL
CUTOFF, LOW IDLE, and HIGH IDLE. In the FUEL CUT-
OFF position, the CONDITION lever controls the cutoff
function of its engine-mounted fuel control unit. From
LOW IDLE to HIGH IDLE, they control the governors of
the fuel control units to establish minimum fuel flow lev-
els. LOW IDLE position sets the fuel flow rate to attain
62% minimum N1 and HIGH IDLE position sets the rate
to attain 71 to 73% minimum N1. The POWER lever for
the corresponding engine can select N1 from the respec-
tive idle setting, up to maximum power. An increase in
low idle N1 will be experienced at high field elevation.
2-24. FRICTION LOCK KNOBS.
Four friction lock knobs placarded FRICTION LOCK
are located on the control pedestal (fig. 2-12), to adjust
friction drag. One knob is below the propeller levers, one
below the CONDITION levers, and two below the POW-
ER levers. When the knobs are rotated clockwise, friction
is increased, opposing movement of the affected lever as
set by the pilot. Counterclockwise rotation of the knobs
will decrease friction, thus permitting free and easy lever
2-25. ENGINE FIRE DETECTION SYSTEM.
a. Description. A fire detection system (fig. 2-14), is
installed to provide an immediate warning in the event of
a fire or overtemperature in the engine compartment. The
routed continuously throughout the engine compartment
terminating in a responder unit. The responder unit is
mounted in the accessory area on the upper left hand