TM 1-1510-262-10
2-30. ENGINE STARTER-GENERATORS.
One starter-generator is mounted on the accessory drive section of each engine. Each starter-generator is able
to function either as a starter or as a generator. In the starter function, 28 volts DC is required to power rotation.
In the generator function, each unit is capable of 400-amperes DC output. When the starting function is selected,
the starter control circuit receives power through the respective 5-ampere START CONTR circuit breaker on the
overhead circuit breaker panel from either the aircraft battery or an external power source. When the generating
function is selected, the starter-generator provides electrical power.
2-31. ENGINE INSTRUMENTS.
The engine instruments are arranged vertically near the center of the instrument panel (Fig. 2-22).
a. Turbine Gas Temperature Indicators. The two TGT gauges on the instrument panel are calibrated in de-
grees Celsius (Fig. 2-22). Each gauge is connected to thermocouple probes located in the hot gases between the
turbine wheels. The gauges register the temperature present between the compressor turbine and power turbine
for the corresponding engine.
b. Engine Torque meters. The two torque meters on the instrument panel indicate torque applied to the pro-
peller shafts of the respective engines (Fig. 2-22). Each gauge shows torque in percent of maximum using two
percent graduations and is actuated by an electrical signal from a pressure sensing system located in the respective
propeller reduction gear case. The torque meters are protected by individual 0.5-ampere circuit breakers placarded
TORQUE METER #1 or #2 on the overhead circuit breaker panel (Fig. 2-12).
c. Turbine Tachometers. The two tachometers on the instrument panel register compressor turbine RPM (N
1 ) for the respective engine (Fig. 2-22). These indicators register turbine RPM as a percentage of maximum gas
generator RPM. Each instrument is slaved to a tachometer generator attached to the respective engine.
d. Oil Pressure/Oil Temperature Indicators. The two gauges on the instrument panel register oil pressure in
PSI and oil temperature in C (Fig. 2-22). Oil pressure is taken from the delivery side of the main oil pressure
pump. Warning annunciators placarded #1 OIL PRESS and #2 OIL PRESS is located in the warning annunciator
panel. A thermal sensor unit which senses the temperature of the oil as it leaves the delivery side of the oil pressure
pump transmits oil temperature. Each gauge is connected to pressure and temperature transmitters installed on the
respective engine. Both instruments are protected by 5-ampere circuit breakers, placarded OIL PRESS and OIL
TEMP #1 or #2 , on the overhead circuit breaker panel (Fig. 2-12).
e. Fuel Flow Indicators. The two gauges on the instrument panel (Fig. 2-22) register the rate of low for con-
sumed fuel as measured by sensing units coupled into the fuel supply lines of the respective engines. The fuel low
indicators are calibrated in increments of hundreds of pounds per hour. Both circuits are protected by 5-ampere
circuit breakers placarded FUEL FLOW #1 or #2 , on the overhead circuit breaker panel (Fig. 2-12).
2-34
