TM 55-1730-229-12
TO 35C2-3-473-1
(2)
Engine power is developed through com-
ENGINE ASSEMBLY.
pression of outside air by a single entry centrifugal com-
pressor. The compressed air, when mixed with fuel and
a.
Inspect engine for leakage at fuel and hy-
ignited, drives a radial inward-flow turbine rotor. The ro-
draulic line fittings. Tighten loose fittings.
tating shaft power of the turbine rotor drives the com-
pressor and the output drive shaft to the gearcase as-
b.
Inspect wiring harness for cuts or abraded
sembly.
wires. Inspect electrical connectors for security of
installation, damage, and corrosion.
b. Compressor Section. The compressor sec-
tion, figure 4-69, consists of an inlet housing (9), a
c.
Inspect engine accessories for security of in-
compressor housing assembly, a single stage cen-
stallation, damage, and corrosion.
trifugal compressor rotor (15), and a diffuser. The
compressor provides compressed air to the turbine sec-
tion, and for external use as bleed air. The inlet housing
let duct (3 and 15, figure 4-68) for cracks, holes, or
assembly houses a planetary gear set (19) which drives
damage. Inspect inlet duct screen (1) for damage by
the gear train in the gearcase assembly (1).
opening bypass door. Remove any foreign material
from screen. Inspect lower duct (15) for loose rivets
and damaged nut plates.
deswril assembly (14), a turbine nozzle, a turbine rotor
(13), a labyrith seal assembly, and a combustion cham-
CHECK VALVES.
ber (10). Compressed air from the compressor section
passes through the deswirl deflector and enters the tur-
NOTE
bine plenum assembly where combustion takes places.
There are two check valves, as shown in figure
The combustion gases flow through the torus scroll and
4-70, View A.
the turbine nozzle to the turbine rotor causing rotation
and driving the planetary gear system, which drives the
a.
Remove.
(See figure 4-70).
gear train in the gearcase assembly. A containment ring
(17) is provided to protect personnel if the blades of the
(1)
Loosen clamps (1) and disconnect drain
turbine were to disintegrate because of an overspeed or
lines (2) from check valves (3).
over temperature condition.
(2)
Remove two check valves (3) with pack-
d. Gearcase Assembly. The gearcase assembly
ing (4). Discard packing.
(item 4, figure 4-64) provides pads (7, 14) for mount-
ing and driving a hydraulic pump and a generator. The
b.
Inspect.
gearcase assembly also provides mounting bosses for
a low oil pressure switch (8), a speed sensor (5), and a
high oil temperature switch (12). An oil pump housing
(1)
Inspect check valve for damage that
is located on the lower front of the gearcase assembly.
would prevent internal valve mechanism from operat-
It encloses a rotary oil pump assembly and provides a
ing. No damage is allowed.
mounting pad for the fuel control unit (9), and mounting
bosses for magnetic drain plugs (10,13).
