User's Manual Part 1

CAS / Part No. 9000000

SYSTEM DESCRIPTION AND INSTALLATION MANUAL

34-43-20

15 Feb 2003

Use or disclosure of information on this page is subject to the restrictions in the proprietary notice of this document.

1--7

The first two levels of situational awareness include:

• Non -- threat Traffic, indicates other targets within the range of the display whose

relative altitude is greater than ±1200 ft. vertically or a distance greater than six

nautical miles from own aircraft.

• Proximity Traffic, indicates the target is within ±1200 ft. vertically or within six

nautical miles of own aircra ft.

The two levels of advisories include:

• Traffic advisories (TA) indicate the range, bearing, and relative altitude of the

intruder to aid in visual acquisition of the intruder.

• Resolution advisories (RA) indicate a vertical maneuver to be performed or

avoided in order to assure safe separation.

Traffic advisories can be displayed on a Vertical Speed Indicator/Traffic and

Resolution Advisory (VSI/TRA) display, Electronic Flight Instrument System (EFIS) or

any instrument that displays the appropriate symbology and conforms to the

definition of ARINC Characteristic 735A.

Resolution advisories can be displayed on the VSI/TRA display, EFIS or any other

indicator that displays the appropriate symbology and conforms to the definitio n of

ARINC Characteristic 735A.

Figure 1--1 shows the various types of intruder equipment and the resulting

advisories. It should be noted that Mode A equipped intruders result in detection and

displa y of TAs only. An intruder not equipped with a transponder is invisible to TCAS.

Communication with another TCAS equipped aircraft is provided by an onboard

diversity Mode S transponder. Only one onboard Mode S transponder is required for

TCAS operation. However, the ACSS TCAS operates with either of two onboard

Mode S transponders, one of which operates as a spare. The transponder in use is

selectable from the Flight Deck. Figure 1--2 shows the communication between two

TCAS equipped aircraft.