Manual

INTRODUCTION

TCAS (an acronym formed from the phrase Traffic Alert and Collision

Avoidance System) is an airborne system used for detecting and

tracking aircraft near your own aircraft. TCAS I includes a TCAS

processor, antennas, a traffic display and a means to control the sys-

tem. The TCAS processor and antennas detect and track other air-

craft by interrogating their transponders. Aircraft detected, tracked,

and displayed by TCAS are referred to as Intruders. TCAS analyzes

the transponder replies to determine range, bearing and relative alti-

tude, if the Intruder is reporting altitude. Should the TCAS processor

determine that a possible collision hazard exists, it issues visual and

aural advisories to the crew. The visual advisory is shown by symbols

on the traffic display. Complementing the traffic display, TCAS pro-

vides appropriate synthesized voice announcements in the cockpit. A

complete list of traffic symbols and announcements is given in the

Theory of Operation and Symbology section of this Pilot’s Guide.

TCAS is unable to detect any Intruding aircraft without an oper-

ating transponder. TCAS can detect and track aircraft with

either an ATCRBS (operating in Mode A or C) or Mode S

transponders.

The traffic display shows the Intruding aircraft’s position. TCAS identi-

fies the relative threat of each Intruder by using various symbols and

colors. The Intruder’s altitude, relative to your own aircraft’s altitude, is

annunciated if the Intruder is reporting altitude. A trend arrow is used

to indicate if the Intruder is climbing or descending more than 500 feet

per minute. TCAS traffic may be displayed on a weather radar indica-

tor, on a dedicated TCAS display, on a TCAS compatible EFIS

Display Unit or a TA/VSI (combination traffic display and vertical

speed instrument).

TCAS modes and functions are controlled by switches located on a

TCAS control panel or in combination with various other controls. A

description of controls is given in the Controls and Displays section of

this Pilot’s Guide.

ATC procedures and the “see and avoid concept” will continue to be

the primary means of ensuring aircraft separation. However, if com-

munication is lost with ATC, TCAS adds a significant backup for colli-

sion avoidance.

Introduction

Effective Date 6/94 006-08746-0000 Rev 2

TCAS I Pilots Guide 2/8/06 3:52 PM Page 2