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
computer. Both NAV and APR annunciators will be illuminated.
Revision 04: 08-15-07
P/N 11934-S20 17 of 24
Cirrus Design Section 9
SR20 Supplements
Glideslope Intercept and Tracking
1. Begin with a reliable ILS signal selected on the NAV receiver.
2. Select autopilot NAV and APR. Airplane must be within 50%
needle deviation of localizer centerline.
3. Select ALT mode. Airplane must be 60% or more below the
glideslope centerline during the approach to the intercept point. If
the above conditions have existed for 10 seconds, GS mode will
arm, the GS annunciator will come on and the ALT annunciator will
remain illuminated. When glideslope intercept occurs, the ALT
annunciator will go out and the system will track the glideslope.
• Note •
If approach vectoring locates the airplane too near the
glideslope at the intercept point (usually the outer marker), the
GS mode can be manually armed by pressing the ALT button
once. Once capture is achieved, GS annunciator will come on
and ALT annunciator will go out.
Section 5 - Performance
There is no change to the airplane performance when the S-Tec
System 55X autopilot is installed.
Section 6 - Weight & Balance
There is no change to the airplane weight & balance when the S-Tec
System 55X autopilot is installed.
Section 7 - Systems Description
Autopilot
The airplane is equipped with an S-Tec System 55X two-axis
Automatic Flight Control System (Autopilot). The autopilot
programmer/computer is installed in the center console radio stack.
The autopilot roll axis uses an inclined gyro in the turn coordinator
case as the primary turn and roll rate sensor. In addition to the turn
coordinator instrument, the roll axis computer receives signals from
the HSI and the #1 NAV/GPS radio. The roll computer computes roll
steering commands for turns, radio intercepts, and tracking. Roll axis
Revision 04: 08-15-07
18 of 24 P/N 11934-S20
Section 9 Cirrus Design
Supplements SR20
steering is accomplished by autopilot steering commands to the
aileron trim motor and spring cartridge.
The pitch computer receives altitude data from the altitude encoder
pressure transducer plumbed into the static system, an accelerometer,
and glideslope information from the HSI and #1 NAV radio. Pitch axis
command for altitude hold, vertical speed hold, and glideslope tracking
is accomplished by pitch computer commands to the elevator trim
motor.
The altitude selector provides altitude and vertical speed pre-select
capability for the autopilot. A pre-programmed altitude and vertical
speed can be input into the altitude selector/alerter and then coupled
to the autopilot. The autopilot will then follow the selected vertical
speed until the selected altitude is reached. Then the altitude selector
will signal the autopilot to hold the selected altitude. The altitude
selector/alerter receives uncorrected altitude data from the same
altitude encoder used by the transponder. In addition to the preselect
functions, the altitude selector provides altitude alert, decision height,
and altitude readout.
28 VDC for autopilot and altitude selector/alerter is supplied through
the 5-amp AUTOPILOT circuit breaker on the Essential Bus.
All Autopilot mode selection is performed by using the mode select
buttons and VS knob on the autopilot programmer/computer in the
center console. Annunciators in the programmer/computer display
window annunciate modes. Refer to Figure 1 for an illustration of the
programmer/computer.
RDY (Ready)– Illuminates when autopilot is ready for engagement.
When the airplane’s Battery Master switch is turned on and the rate
gyro RPM is correct, the RDY annunciator will come on indicating the
autopilot is ready for the functional check and operation. The autopilot
cannot be engaged unless the RDY light is illuminated.
Revision 04: 08-15-07
P/N 11934-S20 19 of 24
Cirrus Design Section 9
SR20 Supplements
HDG (Heading) Mode – When HDG is selected, the autopilot will
engage the HDG mode, fly the airplane to, and hold the heading set on
the HSI. Subsequent heading changes are made using the HDG knob
on the HSI. For smoothest transition to HDG mode, it is recommended
that the airplane be aligned to within 10° of the selected heading
before engaging HDG. The HDG mode is also used in combination
with the NAV mode to set up a pilot selected intercept angle to a
course.
GPSS (GPS Steering) – Pressing NAV twice will cause the autopilot
to go to GPSS for smoother tracking and transitions. When GPSS is
selected, the autopilot can be switched between heading and GPSS
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：
西锐20飞机信息手册CIRRUS DESIGN SR20 AIRPLANE INFORMATION MA(112)
