Section 7 Pilot’s Operating Handbook
Description of Airplane and Systems EXTRA 500
7.14.c Engine Controls
Engine controls are centrally located between the pilot’s and
copilot’s seat on the center console (see
Figure 7-10).
1 Power Lever
The Power Lever allows thrust modulation from takeoff to
maximum reverse. The condition lever is mechanically
connected via the coordinator to the propeller turbine governor
assembly, the gas producer fuel control unit and the beta control
valve. It influences therefore the fuel control as well as the
propeller pitch control system of the engine.
In the range from
FLT IDLE to MAX POWER propeller pitch is
adjusted by the propeller governor to absorb the mechanical
power produced by the engine. Advancing the power lever
towards
MAX POWER increases engine output by
increasing the fuel flow to the engine. As no automatic devices
exist to avoid violations of the torque or TOT limits of the
engine these have to be monitored when increasing engine
power.
In the range from
GRD IDLE to MAX REVERSE the propeller
pitch angle is directly controlled by the power lever
(hydraulically augmented by the Beta Control valve). The fuel
control unit automatically adjusts fuel flow according to the
power demand, which results from selected propeller pitch and
taxi speed.
A mechanic lock avoids inadvertent positioning of the power
lever below the
FLT IDLE position. The lever has to be lifted
before it can be retarded to
GRD IDLE.
2 Condition Lever
The condition lever allows engine starting and shutdown,
propeller feathering and fuel shutoff, and the capability to vary
propeller governor setting to select propeller speed between
1900 and 2030 rpm in flight regimes.
The condition lever is mechanically connected via the
coordinator to the propeller turbine governor assembly and the
gas producer fuel control unit.
In the
FUEL OFF/FEATHER position the fuel flow to the engine
is shut off (engine shut down) and the propeller is feathered.
Propeller feathering is accomplished by opening a pilot valve
allowing oil to be dumped from the propeller operating piston
7-28 26. January 2011
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