Section II: EMERGENCY EQUIPMENT
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.
2-14. FIRST AID KITS.
Four first aid kits are included in the survival kit.
2-15. HAND-OPERATED FIRE EXTINGUISHER.
Repeated or prolonged exposure to
romethane (CF3Br) or decomposition
products should be avoided. The
liquid shall not be allowed to come
into contact with the skin, as it may
cause frost bite or low temperature
burns because of its very low boiling
One hand-operated fire extinguisher is mounted
below the pilot's seat and a second extinguisher, located
on the left cabin sidewall, aft of the cabin door. They
are of the monobromotrifluoromethane (CF3Br) 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
Engine fire extinguisher systems are
described in Section III.
Section III. ENGINES AND RELATED SYSTEMS
The aircraft is powered by two PT6A-41 turboprop
engines (fig. 2-10). 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 forced 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 turbine and
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 turbine
tachometer transmitter. The reduction gearbox forward
of the power turbine provides gearing for the propeller
and drives the propeller tachometer transmitter, the
governor. A torque limiter is incorporated on the front
case of the propeller reduction gearbox to maintain
developed engine torque within design limits.
2-17. ENGINE COMPARTMENT COOLING.
The forward engine compartment including the
accessory section is cooled by air entering around the
exhaust stack cutouts, the gap between the propeller
spinner and forward cowling, and exhausting through
ducts in the upper and lower aft cowling.
2-18. AIR INDUCTION SYSTEMS GENERAL.
Each engine and oil cooler receives ram air
ducted 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.