Eagle ICA-D212-725, Instructions Manual

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ICA-D212-725 (76)
Page 11 of 21
CHAPTER 76 – ENGINE CONTROLS (76-00-00)

COPYRIGHT

2007 BY DART AEROSPACE LTD.

THIS DOCUMENT IS PRIVATE AND CONFIDENTIAL AND IS SUPPLIED ON THE EXPRESS CONDITION THAT IT IS NOT TO BE USED FOR ANY PURPOSE OR COPIED OR COMMUNICATED TO ANY
OTHER PERSON WITHOUT WRITTEN PERMISSION FROM DART AEROSPACE LTD.
Revision:
0
Date: 07.05.31
76.3 POWER LEVER CONTROLS
76.3.1 Power Lever Controls
The engine fuel and power control system
permits the pilot to obtain maximum
performance from the engine with a minimum of
attention. Under normal flight conditions the N2
rotor speed is controlled by the power turbine
speed governor. The N1 speed governor
safeguards the engine against overloading, and
on acceleration and deceleration. The control
avoids engine damage or combustion blowout
due to sudden changes in power.
76.3.1.1 Power Lever Control System
A mechanical linkage system, actuated by a
twist grip on the collective pitch control lever,
provides manual control of the power lever on
the fuel control unit, modulating the engine from
zero to full power by controlling the gas producer
(N1) rpm. The linkage is a series of control
rods, and bellcranks, with adjustable tubes at
two locations in the series to the fuel control
lever. One bellcrank (station 158.00) has an
adjustment to provide correct travel of the
engine airframe-mounted linkage. The power
lever shaft is serrated to accept a control arm,
and has a quadrant marked with power settings
in the travel range between stops, pre-adjusted
by the engine manufacturer or overhaul facility.
An adjustable flight idle stop and release, on the
bellcrank (station 191.57) located below the
engine service deck left side, contacts the
plunger of a solenoid to arrest travel of the
control linkage at flight idle position, when power
is reduced from higher settings. Stop release is
accomplished by use of the ENGINE IDLE
STOP REL push button switch on the pilot’s
collective lever to retract the solenoid plunger.
A bleed air heater shut-off switch activated by a
cam on the collective lever jackshaft is activated
when high collective stick is required, which
electrically closes the bleed air valve.
NOTE
The idle stop plunger will not retract
if excessive pressure is applied by
the twist grip toward the closed
position.
76.3.1.2 Rigging – Power Lever
Controls
NOTE
Rigging of power lever control
system is normally accomplished in
three operations: rigging-power
lever controls, rigging-flight idle
solenoid, and rigging-bleed air
heater shut-off switch. (Refer to
Chapter 67 for rigging bleed air
heater shut-off switch.)
Refer to BHT-ALL-SPM for specifications and
source.
MATERIALS REQUIRED
NUMBER NOMENCLATURE
C-101 Corrosion Preventive Compound
NOTE
If dual controls kit P/N 212-706-
005-003 or -007 is installed refer
to BHT-212-Sl-4 for installation
and removal instructions.
76.3.1.2.1 Comply with the following
general procedures when rigging power lever
controls.
76.3.1.2.1.1 When a rigging procedure
requires a specific position to accomplish steps,
manually hold controls in position or secure
controls in position with pilot friction adjustment.
76.3.1.2.1.2
Tolerance for rigging
dimensions is ± 0.030 in. (0.76 mm) unless
stated otherwise.
76.3.1.2.1.3
All adjustable control tubes shall
have a maximum of 1.00 in. (25.4 mm) of
exposed threads after adjustment. If control