曝光台 注意防骗
网曝天猫店富美金盛家居专营店坑蒙拐骗欺诈消费者
bus, but power can be restored to that bus by closing a
bus tie switch. Closing this switch connects the buses
and allows the operating generator to power both.
Power distribution buses are protected from short
circuits and other malfunctions by a type of fuse called
a current limiter. In the case of excessive current
supplied by any power source, the current limiter will
open the circuit and thereby isolate that power source
and allow the affected bus to become separated from
the system. The other buses will continue to operate
normally. Individual electrical components are
connected to the buses through circuit breakers. A
circuit breaker is a device which opens an electrical
circuit when an excess amount of current flows.
PRIMARY
INVERTER
SECONDARY
INVERTER
LEFT
MAIN
BUS
RIGHT
MAIN
BUS
LEFT
ESSENTIAL
BUS
RIGHT
ESSENTIAL
BUS
AMPS
0
100
200
300
400 DC
VOLTS
0
28
35
AMPS
0
100
200
300
400
REGULATOR REGULATOR
LEFT
GENERATOR
BUS
BATTERY
CHARGING
BUS
RIGHT
GENERATOR
BUS
LEFT
GENERATOR/
STARTER
LEFT
GENERATOR/
STARTER
G.P.U.
LEFT
BATTERY
RIGHT
BATTERY
OVER
VOLTAGE
CUTOUT
Current Limiter
Circuit Breaker
Bus
Figure 14-10. Simplified schematic of turboprop airplane electrical system.
Ch 14.qxd 5/7/04 10:09 AM Page 14-9
14-10
OPERATIONAL CONSIDERATIONS
As previously stated, a turboprop airplane flies just like
any other piston engine airplane of comparable size
and weight. It is in the operation of the engines and
airplane systems that makes the turboprop airplane
different from its piston engine counterpart. Pilot
errors in engine and/or systems operation are the most
common cause of aircraft damage or mishap. The time
of maximum vulnerability to pilot error in any gas
turbine engine is during the engine start sequence.
Turbine engines are extremely heat sensitive. They
cannot tolerate an overtemperature condition for more
than a very few seconds without serious damage being
done. Engine temperatures get hotter during starting
than at any other time. Thus, turbine engines have
minimum rotational speeds for introducing fuel into
the combustion chambers during startup. Hypervigilant
temperature and acceleration monitoring on
the part of the pilot remain crucial until the engine is
running at a stable speed. Successful engine starting
depends on assuring the correct minimum battery
voltage before initiating start, or employing a ground
power unit (GPU) of adequate output.
After fuel is introduced to the combustion chamber
during the start sequence, “light-off” and its associated
heat rise occur very quickly. Engine temperatures may
approach the maximum in a matter of 2 or 3 seconds
before the engine stabilizes and temperatures fall into
the normal operating range. During this time, the pilot
must watch for any tendency of the temperatures to
exceed limitations and be prepared to cut off fuel to
the engine.
An engine tendency to exceed maximum starting
temperature limits is termed a hot start. The temperature
rise may be preceded by unusually high initial fuel
flow, which may be the first indication the pilot has
that the engine start is not proceeding normally.
Serious engine damage will occur if the hot start is
allowed to continue.
A condition where the engine is accelerating more
slowly than normal is termed a hung start or false
start. During a hung start/false start, the engine may
1. Before Takeoff
Checks – Completed
2. Lineup Checks – Completed
Heading Bug – Runway Heading
Command Bars – 10 Degrees Up
3. Power – Set
850 ITT / 650 HP
Max: 923 ITT / 717.5 HP
7. Ign Ovrd – Off
6. Gear Up
8. After T/O
Checklist
Yaw Damp
– On
9. Climb Power – Set
850 ITT / 650 HP
98 – 99% RPM
11. Climb Speed – Set
Climb Checks –
Completed
10. Prop Sync – On
These are merely typical procedures. The
pilot maintains his or her prerogative to
modify configuration and airspeeds as
required by existing conditions, as long as
compliance with the FAA approved Airplane
Flight Manual is assured.
NOTE:
5. Rotate at 96 – 100 KIAS
4. Annunciators – Check
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址:
AIRPLANE FLYING HANDBOOK 飞机飞行手册下(65)