TM 1-1510-218-10
2-31
Section II. EMERGENCY EQUIPMENT
2-16. DESCRIPTION.
The equipment covered in this section includes
all emergency equipment, except that which forms part
of a complete system. For example, landing gear
system, etc. Chapter 9 describes the operation of
emergency exits and location of all emergency
equipment.
2-17. FIRST AID KITS.
Three first aid kits are installed.
2-18. HAND-OPERATED FIRE EXTINGUISHER.
Repeated or prolonged exposure to high
concentrations
of
CF3Br
gas
or
decomposition
products
should
be
avoided. The liquid shall not be allowed to
come into contact with the skin, as it may
cause frostbite or low temperature burns
because of its very low boiling point.
One hand-operated fire extinguisher is mounted
below the pilot's seat and a second extinguisher is
mounted beneath the aft left seat. They are of the
CF3Br gas type. The extinguisher is charged to a
pressure of 150 to 170 psi, and emits a forceful
stream. Use an extinguisher with care within the
limited area of the cabin to avoid severe splashing.
NOTE
Engine
fire
extinguisher
systems
are
described in Section III.
2-19. SURVIVAL KITS.
There are two different survival kits authorized
for installation in the aircraft. Depending on the
anticipated mission, either an over water or overland
kit may be installed. The kit is carried in the aft
baggage area of the cabin.
2-20. SURVIVAL RADIOS.
Provisions are installed for installation of two
AN/PRC-90 Radio Sets: one on the partition aft of the
pilot's seat and one adjacent to the cabin entrance
door. Each radio is equipped with a placard giving
specific operating instructions.
Section III. ENGINES AND RELATED SYSTEMS
2-21. DESCRIPTION.
The aircraft is powered by two PT6A turboprop
engines. Refer to Figure 2-14. The engine has a
three stage axial, single stage centrifugal compressor,
driven by a single stage reaction turbine. The power
turbine, a two-stage reaction turbine, counter-rotating
with the compressor turbine, drives the output shaft.
Both the compressor turbine and the power turbine are
located in the approximate center of the engine with
their shafts extending in opposite directions. Being a
reverse flow engine, the ram air supply enters the
lower portion of the nacelle and is drawn in through the
aft protective screens. The air is then routed into the
compressor. After it is compressed, it is forc ed into
the annular combustion chamber and mixed with fuel
that is sprayed in through 14 nozzles mounted around
the gas generator case. A capacitance discharge
ignition unit and two spark igniter plugs are used to
start combustion. After combustion, the exhaust
passes through the compressor turbine and two
stages of power turbines then is routed through two
exhaust ports near the front of the engine. A
pneumatic fuel control system schedules fuel flow to
maintain the power set by the gas generator power
lever. The accessory drive at the aft end of the engine
provides power to drive the fuel pumps, fuel control,
the oil pumps, the refrigerant compressor (right
engine), the starter/generator, and the tachometer
transmitter. The reduction gearbox, forward of the
power turbine, provides gearing for the propeller and
drives the propeller tachometer transmitter, the
propeller overspeed governor, and the propeller
governor.
2-22. ENGINE COMPARTMENT COOLING.
The forward engine compartment, including the
accessory section, is cooled by air entering around the
exhaust stub cutouts, the gap between the propeller
spinner and forward cowling, and exhausting through
ducts in the upper and lower aft cowling.
2-23. AIR INDUCTION SYSTEMS – GENERAL.
Each engine and oil cooler receives ram air
dueled from an air scoop located within the lower
section of the forward nacelle. Special components of
the engine induction system protect the power plant
from icing and foreign object damage.
WARNING
