Exhaust Gase Temperature System; Engine Tachometer System; Engine Torque System - THRUSH S2R – G10 Maintenance Manual

AIRCRAFT MAINTENANCE MANUAL
Bourdon Tube principle, so that the
system does not require any electricity.
Instead, fuel is piped to the gauge from
the top of the engine fuel control unit.
Low fuel pressure should be taken as an
indication of a problem.
pressure can be caused by a bad
engine driven fuel pump, a clogged
engine or airframe fuel filter, or a
blockage or restriction in a line or screen
somewhere in the fuel supply system. It
could also obviously indicate empty fuel
tanks.
If the fuel tanks are not empty, then
turning on the auxiliary fuel pump could
keep the engine running long enough to
make a precautionary landing. It is not
a good practice to leave the aux fuel
pump running continuously, however.
EXHAUST GASE TEMPERATURE
SYSTEM
The TPE331-10 engine is equipped with
a thermocouple array just forward of the
exhaust flange. This array sends a
signal, through a compensator, the the
EGT gauge in the cockpit.
compensator should be pre-set at the
time of overhaul.
Maximum allowed EGT for starting is
770ºC for one second. The rest of the
time the maximum EGT is dependent on
the OAT, per the following chart.
EGT LIMIT
OAT, ºC
45
35
25
15
5
-5
-15
8-8
Page
THRUSH AIRCRAFT, INC – MODEL S2R-G10
Low fuel
The
EGT, ºC
600
590
580
570
560
550
540
The EGT gauge has an external marker
(bug) that can be set at the maximum EGT
value for existing conditions.

ENGINE TACHOMETER SYSTEM

The tachometer indicates the percentage of
maximum RPM the engine is turning at,
which must be kept within a specified
range. The propeller RPM is directly
proportional to engine RPM, since the
TPE331 is a direct-shaft engine. An over-
speed condition would thus indicate a prop
governor or prop blade mechanism failure.
An inability to produce desired RPM when
the engine is putting out adequate power
(torque) would indicate a propeller pitch
mechanism problem.
The tachometer system is electronic, and
therefore functions only when supplied with
electrical power by the airplane.
system has a signal generator mounted on
the engine case which supplies digital
information to the
tachometer indicator interprets this digital
information and displays it with a needle
and scale.

ENGINE TORQUE SYSTEM

Engine torque is a measure of the power
the engine is putting out at the propeller
shaft. For the Garrett TPE331-10 engine,
maximum torque
horsepower. Torque is proportional to the
difference between the oil pressure at the
source port and atmospheric pressure.
The torque gauge indicates this pressure
rather than pound-feet or percent of
maximum, and each engine has a slightly
different pressure
maximum allowed 900 SHP or 100%
torque. This maximum gauge pressure
(PSIG) is determined after overhaul during
the test cell run and is recorded in the
engine log book. The PSIG representing
100% torque is recorded on a placard on
the instrument panel near the torque gauge.
In addition, the torque pressure gauge has
The
indicator. The
indicates 900 shaft
that indicates the
Effective: 03/26/2010