pitch hold can be used to ly to the selected altitude. When reaching the bracket altitude, the system automatically
switches to the ALT SEL CAP mode and the previous pitch mode is cancelled. A command is then generated to
asymptotically capture the selected altitude. The ALT SEL mode is cancelled in altitude hold (ALT) or after glides-
lope capture. ALT SEL capture is annunciated on the PFD by a green ASEL at the vertical capture annunciation
location. To indicate the transition to capture, ASEL will be enclosed in a white box for 5 seconds.
The aircraft will remain in the ALT SEL capture mode until the following conditions exist simultaneously:
ALT error is less than 25 feet
ALT rate is less than 5 feet per second
At this time, the altitude select (ALT SEL) mode will be dropped and the system will be placed in the altitude hold
(ALT) mode. The ALT SEL CAP mode will be dropped and the ALT SEL ARM mode will be automatically reselected
following an ALT SEL knob motion or a pitch wheel actuation. Perform the following steps to ly to a preselected
altitude using the altitude select mode (ALT SEL):
(a) Set selected altitude on altitude preselector.
(b) Select pitch hold, VS, or IAS mode, descend or ascend toward selected altitude.
(c) Depress ALT SEL pushbutton button-indicator on light director mode selector panel. ALT SEL mode is
The altitude lare point (ALT SEL CAP) is a nonlinear function, dependent upon vertical speed and dis-
tance to the selected altitude.
(d) ALT SEL capture is dropped and ALT HOLD is automatically engaged.
Cancel the ALT SEL capture sub mode by:
Moving the ALT SET knob on the altitude preselector.
Moving the pitch wheel on the autopilot controller.
Selecting on or captured any other vertical mode.
Coupling to the cross-side FMS.
Selecting an alternate ATT source on the display controller.
(16) Go-around mode (wings level). The go-around mode is normally used to transition from an ap-
proach to a climb when a missed approach has occurred. Go-around mode is selected by depressing the
GO-AROUND switch located on the left power lever. With go-around selected, all light director modes are
cancelled, and the autopilot is disengaged. The pilot will see a wings level command and a 7-degree climb angle
will be presented on the PFD. When go-around is selected, the autopilot will automatically disengage, and the yaw
damper will automatically engage.
SECTION IV. TRANSPONDER AND RADAR
3-21. RADAR AND TRANSPONDER EQUIPMENT GROUP DESCRIPTION.
The radar and transponder group consists of a weather radar, lightning sensor system, and transponder. The
transponder and radar group includes identiication, position, emergency tracking system, and a radar and light-
ning sensor system to locate potentially dangerous weather areas.
3-22. WEATHER RADAR SYSTEM.
The WXP-850A/B Weather Radar Panel provides the data processing, mode control, range selection, and other
system operating controls for the TWR-850 Turbulence Weather Radar System. Weather radar information from
the WXP-850A/B is displayed on the MFD (Multi-Function Display) which is part of the Universal FMS (UNS-1F/EFI-
890R Display System). The TWR-850 system provides the following display and performance features:
A 4-color weather and turbulence display: green, yellow, red, and magenta, plus the black screen itself.
PAC (Path Attenuation Correction), with a PAC Alert arc appearing in yellow at the perimeter of the display.
GCS (Ground Clutter Suppression).
AUTO (AUTO tilt).