Engine Air Inlet Anti-Ice System.
Description. A small duct, facing into the
exhaust flow of the engine's 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 to the
engine's right exhaust stack. The continuous flow of hot
engine exhaust gases heats the engine air inlet lip,
preventing the formation of ice.
exchanger, located in the engine accessory case,
operates continuously and automatically to heat the fuel
sufficiently to prevent ice from collecting in the fuel
control unit. Each fuel control unit is also protected
against ice. Fuel control heat is automatically provided
during all engine operations.
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 residual 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 accomplished by adjusting the engine gas
generator (N1) speed. N1 speed is controlled by 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 moving 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
The two power levers are located in the control
pedestal (fig. 2-11), 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.
Distinct movement (pulling up and then aft on the power
lever) by the pilot is required for operation in the ground
fine and reverse ranges. Upper 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 in the control
pedestal (fig. 2-11). Each lever starts and stops the fuel
supply, and controls the idle speed for its engine. The
levers have three placarded positions: FUEL CUTOFF,
LOW IDLE, and HIGH IDLE. In the FUEL CUTOFF
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 levels.
LO IDLE position sets the fuel flow-rate to attain 60 to
62% (at sea level) 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
the respective idle setting, up to maximum power. An
increase in low idle N1 will be experienced at high field
2-24. FRICTION LOCK KNOBS.
Four friction lock knobs (fig. 2-11) are located in
the control pedestal to adjust friction drag. One knob is
below the propeller levers, one below the condition
levers, and two below the power 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
movement. Two FRICTION LOCK placards are located
in the pedestal adjacent to the knobs.
2-25. ENGINE FIRE DETECTION SYSTEM.
a. Description. A fire detection system is
installed to provide an immediate warning in the