Hawker Beechcraft Hawker 800XP, Руководство по эксплуатации для пилотов

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Page 2-38
Pilot’s Operating Manual
Revision A1: Nov, 2002
Sub-section 2
ENGINES
Hawker 800XP Pro Line 21
Section III - SYSTEMS DESCRIPTION
OPERATION
In both automatic and manual modes the engine fuel computers limit maximum takeoff power to the
APR rating although under normal conditions, the APR control unit electrically trims down the settings
to the lower normal ratings. When the APR is triggered the control unit allows the computers to reset to
the APR ratings; normal engine response to the thrust lever movement is retained.
When armed, APR is triggered automatically if the engine N
2
signals, received from the synchronizer
and compared by the APR controller, differ by more that 5% N
2.
Increase in thrust is obtained by allowing the engines to be run at higher operating limits; the N
2
rotor
speed increasing approximately 0.75% (max) and the interstage turbine temperature (ITT) rising
approximately 18
°
C (max).
Automatic Mode
In auto mode the system functions in conjunction with the engine synchronizer system.
Manual Mode
When armed, to cater for an auto mode malfunction, the system may also be triggered by manual
selection of APR OVRD.
NOTE: There is a penalty in terms of engine life whenever an engine operates at APR levels - see
the Airplane Flexible Maintenance Schedule for further details. Therefore manual selection
of APR should only be made when it is essential to do so.
To cancel APR mode after manual selection, both the APR OVRD and APR ARM switches should be
delatched. If only the APR ARM switch is delatched, APR will be cancelled but will be triggered again
as soon as the APR ARM switch is pushed.
Failure Modes
Failure of electrical power to the APR/sychronizer controller will also result in both fuel computers
resetting to the APR ratings.
The synchronizer must be serviceable to supply N
2
comparisons for the APR auto mode. Manual
APR OVRD is independent of N
2
signals.
An engine fuel computer must be serviceable and selected to AUTO in order to respond to APR. Should
an engine computer fail, or is selected to manual, with APR armed, APR will be triggered in the other
engine if engine speed differences exceed 5% N
2
.