Physical Description

The TCAS computer is a 6 MCU size unit. It weighs 28 lbs (11.3 kg).

Functional Description

The TCAS computer transmits 1030 MHz pulse-coded interrogation signals. It receives 1090 MHz pulse-coded reply signals from intruder airplanes with an ATC transponder.

Front Panel LED Indications

These are the status light emitting diodes (LEDs):

· A green PASS to show that there is no TCAS computer

failure

· A red FAIL to show a TCAS computer failure

· A red XPNDR to show an ATC transponder interface failure

· A red UPPER ANT to show a top TCAS antenna failure

· A red LOWER ANT to show a bottom TCAS antenna failure

· A red RAD ALT to show no radio altitude data from the RA

· A red HDNG to show no heading data from the ADIRU

· A red R/A to show a DEU display function failure

· The red T/A does not operate.

Front Panel Self-Test

You push the test switch on the front panel to start a test of the TCAS. The LED indications come on to show system status.

Performance Management Recording

The TCAS computer has a slot for a Personal Computer

Memory Card International (PCMCIA) card. The recorder

function provides the capability to store information about

TCAS events for post-flight analysis. These are the RECORD light emitting diodes (LEDs):

· An ACTIVE to show card recording

· A FULL to show card recording complete.