erald Flashcards
A basic understanding of how engine instruments work is
an important part of the knowledge you must have as an
engine operator and troubleshooter
are the most widely used of
all the instrument markings and
usually indicate a safe, or normal
range of operation.
Green arcs
are used to indicate an
allowable range of operations under a
unique set of circumstances.
Blue arcs
indicates a precautionary
range of time limited operation permitted
by the manufacturer.
yellow arc
indicates a maximum or minimum safe
operating limit. Operation beyond a red
line typically results in a dangerous
operating condition.
RED ARCS
is measured at the carburetor entrance by a
temperature sensing bulb in the ram air intake
duct. The sensing bulb senses the air
temperature in the carburetor and then sends a
signal to a cockpit instrument that is calibrated
in degrees Centigrade.
CARBURETOR AIR TEMPERATURE (CAT) GAUGE
Some engines have a fuel pressure gauge
that displays the pressure of fuel
supplied to the carburetor or fuel control
unit. Most fuel pressure instruments
display fuel pressure in pounds per
square inch (psi) and provide indications
to the pilot that the engine is receiving
the fuel needed for a given power
setting.
FUEL PRESSURE GAUGE
measures the rate of fuel an engine burns in
gallons per hour or pounds per hour. This
provides the most accurate indication of an
engine’s fuel consumption.
FUEL FLOW INDICATOR
In addition to a fuel flow gauge, some
aircraft are equipped with fuel
totalizers.
computerized fuel system
(CFS)
measures
the absolute pressure of the fuel air mixture
within the intake manifold.
A manifold absolute pressure gauge
allows a pilot
to monitor the temperature of the oil
entering the engine. This is important
because oil circulation cools the engine
as it lubricates the moving parts.
OIL TEMPERATURE GAUGE
The engine lubrication system supplies oil
under pressure to the moving parts of the
engine. To allow a pilot to monitor the
effectiveness of a given lubrication system, all
aircraft engines are equipped with an oil
pressure gauge that is calibrated in pounds per
square inch.
OIL PRESSURE GAUGE
The engine temperature can have a dramatic impact
on engine performance. Therefore, most
reciprocating engine powered aircraft are equipped
with gauge that
allows a pilot to monitor engine temperatures.
CYLINDER HEAD TEMPERATURE GAUGE
Most cylinder head temperature gauges are
galvanometer-type
is a circuit
consisting of two dissimilar metal wires connected
together at two junctions to form a loop.
thermocouple
Another performance monitoring instrument often used in
reciprocating engine installations. A gauge measures the
temperature of the exhaust at some point past the
exhaust port.
EXHAUST GAS TEMPERATURE
An engine’s crankshaft rpm is displayed by a
tachometer that is calibrated in hundreds of rpm.
The tachometer is a primary engine instrument
used extensively by a pilot to monitor engine
condition and verify that the engine is developing
the appropriate rpm and power output for a
given throttle setting.
TACHOMETER