2-16. AIR INDUCTION SYSTEMS GENERAL.
Each engine and oil cooler receives ram air
ducted from separate air inlets located within the lower
section of the forward nacelle. Induction system
components protect the power plant from icing and
reduce the possibility of foreign object damage.
2-17. FOREIGN OBJECT DAMAGE CONTROL.
The engine has an integral air inlet screen
designed to obstruct objects large enough to damage
The engine anti-ice system (ice vanes)
should be on (extended) for all ground
operations to minimize ingestion of ground
debris. Turn off engine anti-ice (retract ice
vanes) to maintain engine temperatures
2-18. ENGINE ICE PROTECTION SYSTEMS R .
a. Inertial Separator. An inertial separation
system is built into each engine air inlet to prevent
moisture particles from entering the engine inlet
plenum under icing conditions. A movable vane and a
bypass door are lowered into the air stream when
operating in visible moisture at 5 °C or colder, by
energizing electrical actuators with the switches,
placarded LEFT and RIGHT ENGINE ANTI-ICE ON /
OFF, located on the pilot's subpanel. The system
incorporates an electrical backup system that operates
identically to the main system. The back-up ice vane
system is controlled by two switches placarded LEFT
and RIGHT ACTUATOR MAIN / STANDBY, located
on the pilot's subpanel. If the main system fails,
placing the switch in the STANDBY position will allow
use of the back-up system. Electrical protection is
provided through two 5-ampere circuit breakers
placarded LEFT and RIGHT MN ENG ANTI-ICE and
two 5-ampere circuit breakers, placarded LEFT and
RIGHT STBY ENG ANTI-ICE, located on the right
sidewall circuit breaker panel.
b. Engine Ice Protection Systems Operation.
The vane deflects the ram airflow slightly downward to
introduce a sudden turn in the airflow to the engine.
Because of their greater momentum the particles
continue undeflected and are discharged overboard.
Once the ice vane system is actuated, the
extended position of the vane and bypass door is
indicated by green annunciators, placarded L and R
ENG ANTI-ICE, located on the caution/advisory panel.
If for any reason the vane(s) do not attain the selected
position within 33 seconds, a yellow L or R ENG ICE
FAIL annunciator will illuminate on the caution/
advisory panel. In this event, the appropriate LEFT or
RIGHT ACTUATOR switch should be placed in the
STANDBY position. Once the vane is successfully
positioned, using the standby system, the yellow
annunciator(s) will extinguish and the applicable green
LEFT or RIGHT ENG ANTI-ICE annunciator(s) will
c. Engine Anti -Ice System.
(1) Air Inlet. A small duct, which faces into
the exhaust flow in the left exhaust stack of each
engine, 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 right exhaust stack.
The continuous flow of hot engine exhaust gases
heats the engine air inlet lip, preventing the formation
exchanger, located in the engine accessory case,
operates continuously and automatically to heat the
fuel sufficiently to prevent ice from collecting in the fuel
(3) Fuel Control Heat. The engine fuel
control unit is protected from icing by the fuel control
heater, which is actuated by movement of its
respective condition lever. The fuel control heater
circuit breaker, placarded LEFT and RIGHT FUEL
CONTROL HEAT, is located on the right sidewall
circuit breaker panel.
2-19. ENGINE ICE PROTECTION SYSTEMS T3 F3 ..
a. Ice Vanes (Inertial Separator System). An
inertial separation system is built into each engine air
inlet to prevent moisture particles from entering the
engine inlet plenum under icing conditions. A movable
vane and a bypass door are lowered into the airstream
when operating in visible moisture at an OAT or SAT
of +5°C or colder (IOAT or TAT of +10°C or colder for
in flight) with the switches, placarded ICE VANE
EXTEND / RETRACT, located on the lower left
The vane deflects the ram airstream slightly
downward to induce a sudden turn in the airstream to
the engine causing the moisture particles to continue
undeflected, because of their greater momentum, and
to be discharged overboard.
While in the icing flight mode, the extended
position of the vane and bypass door is indicated by
green annunciator lights, L ICE VANE EXT and R ICE