User's Manual Part 2

T
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CAS / Part No. 9000000
SYSTEM DESCRIPTION AND INSTALLATION MANUAL
34-43-20
15 Feb 2003
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4--86
(7) Decision Height /Minimum Descent Altitude Selection (DH/MDA)
The DH/MDA Discrete input is used select either the Decision Height or Minimum
Descent Altitude input. The selected DH or MDA is used to determine Altitude
Call--Outs.
(8) Below Decision Height
The Below Decision Height Discrete input is to trigger Altitude Call--Outs.
(9) Aircraft On Ground
The Aircraft On Ground Discrete input is shared between the TCAS and TAWS
functions with separate internal wiring.
(10) ILS Back Course
The ILS Back Course Discrete input is used to indicate that a back--course landing
approach has been selected/detected.
A back --course approach is a landing approach in which the localizer signal lobes
have been reversed. Typically the back--course switch is selected on the Auto--Pilot
control panel and will compensate for the reversal of the localizer radio beams.
Additionally, when Back--Course is selected, the Glideslope radio beams become
invalid )resulting in the Glideslope Inhibit discrete being set).
(11) Altitude Callout Disable
The Altitude Callout Disable Discrete input is used to disable all altitude call --outs.
(12) Engine Out
When set, the Engine Out discrete indicates that one or more aircraft engines is
inoperative. The Engine Out data is used as part of the aircraft performance
calculations during a TAWS or Windshear event.
F. TAWS/RWS Digital Output Data
(1) GCAM Event Data
The T
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CAS TAWS/Windshear events are caused by terrain and weather conditions.
An event begins when a terrain or weather condition causes the T
2
CAS to declare a
TAWS/Windshear caution or warning alert or when the aircraft telemetry causes a
Bank Angle Callout. This data is set at each apparition of alert (cautio n or warning)
and contains information about the triggering event. The T
2
CAS then transmits the
GCAM Event Data over one of the programmable ARINC 429 output Buses in
Table 4--14.
Table 4--23 shows the GCAM Event Data Labels transmitted on the A429 output Bus.