User's Manual

SYSTEM DESCRIPTION AND INSTALLATION MANUAL
TCAS 3000 Traffic Alert and Collision Avoidance System
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Page 53
15 Dec 2005
Figure 51. VSI/TRA Fault Warning Display
4. System SelfTests
A. Cockpit Display Test Modes
The TCAS 3000 System provides two types of test modes; a short functional test mode
and an extended maintenance test. Both test modes can be activated by the TEST
button or switch on the ATC/TCAS Control Panel. The short test mode can also be
activated by a central maintenance computer (CMC) or a central fault display interface
unit (CFDIU). The extended test mode can only be initiated at the end of the short test.
The short test mode is inhibited in the air if the SelfTest Inhibit programming pin
(RBP8E) is grounded.
(1) Short Test Mode
The short test mode provides a flight deck initiated functional test of the TCAS RA
and TA displays and associated TCAS interfaces. It also provides an aural
annunciation of the TCAS system status.
The short test mode is available in all TCAS operational modes (Standby, TA Only, or
TA/RA) when on the ground. If a TA or RA occurs while airborne, the test is
terminated and normal operating status is resumed. The test mode is also
terminated if any of the Advisory Inhibit discrete inputs (grounds) are received on pins
RBP5A, RBP5B, RBP5C, or RBP5D.
Push and hold the TEST button/switch on the ATC/TCAS controller for a few seconds
to start the test. When the test mode becomes active, the words “tcas test” are
transmitted once aurally. In addition to the TCAS test pattern, RA indications and a
red TCAS TEST annunciation are displayed on the applicable display(s). Refer to
Figure 118 for a typical test pattern display on the VSI/TRA.