Page 145 - The Jet Engine

Controls and instrumentation

5. On engines fitted with afterburning, single lever 6. On a turbo-propeller engine, the throttle lever is
control is maintained, although a further fuel system interconnected with the propeller control unit
is required to supply and control the fuel to the (P.C.U.), thus maintaining single lever operation of
afterburner (Part 16). the engine. Similarly, the throttle control lever of a
helicopter is interconnected with the collective pitch
lever, so ensuring that an increase in pitch is
accompanied by an increase in engine power,

7. The fuel system (Part 10) incorporates a high
pressure fuel shut-off cock to provide a means of
stopping the engine. This may be operated by a
separate lever, interconnected with the throttle lever,
or electrically actuated and controlled by a switch on
the pilot's instrument panel.
8. A turbo-jet engine fitted with a thrust reverser
usually has an additional control lever that allows
reverse thrust to be selected (Part 15). On a turbo-
propeller engine, a separate control lever is not
required because the interconnected throttle and
P.C.U. lever is operated to reverse the pitch of the
propeller.
INSTRUMENTATION
9. The performance of the engine and the operation
of the engine systems are shown on gauges or by
the operation of flag or dolls-eye type indicators. A
diagrammatic arrangement of the control and instru-
mentation for a turbo-jet engine is shown in fig. 12-2.

Fig. 12-2 Diagrammatic arrangement of engine control and instrumentation.

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