TCAS

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Honeywell

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Telephone: (425) 885-3711

FAX: (425) 885-2061

ACS-5059 Rev. - 5 - 02/2000

ACS-5059 • Rev 5 - 02/2000Collision Avoidance System User’s Manu a l

Collision Avoidance System User’s Manu a l

TCASII/ACASII

The info rmation contained in this manual is for re fe rence use only.If any info rmation contained herein conflicts with similar info rm a-tion contained in the Airplane Flight Manu a l , the info rmation in theAirplane Flight Manual shall take pre c e d e n c e .

1ACS-5059 • Rev 5 - 02/2000Collision Avoidance System User’s Manu a l

Table of Contents

Section 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

Section 2 Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

Section 3 Controls & Displays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Section 4 System Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

Section 5 Appendix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

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SECTION 1Introduction

Scope This manual applies to systems which are compliant toRTCA DO185A MOPS Change 7.0 and RTCA “DO-185” MOPS Change 6.04a. These systems are re f e r re dto as TCAS II (Traffic Alert and Collision Avo i d a n c eSystem) in the United States and ACAS II (Airborn eCollision Avoidance System) intern a t i o n a l l y. The term i-nology is used interchangeably and, for the purpose ofdiscussion, TCAS II will be the terminology used in thismanual.

TCAS II is a system used for detecting and trackingaircraft in the vicinity of your own aircraft.By interro-gating their transponders it analyzes the replies todetermine range,bearing,and if reporting altitude,therelative altitude of the intruder. Should the TCAS IIprocessor determine that a possible collision hazardexists,it issues visual and audio advisories to thecrew for appropriate vertical avoidance maneuvers.TCAS is unable to detect any intruding aircraft withoutan operating transponder.

There are two types of cockpit displays for TCAS II,the Resolution Advisory (RA) display and the TrafficAdvisory (TA) display.The RA display is incorporatedinto the vertical speed indicator (VSI).By illuminatingred and green areas around the dial it displays therequired rate,or limitation of climb or descent,toavoid a possible collision.

The TA display shows the intruding aircraft’s relativeposition and altitude with a trend arrow to indicate ifit is climbing or descending at greater than 500 feetper minute.This TA display may be provided on theweather radar indicator, on a dedicated TCAS displayor a TA/VSI display.

The TA display identifies the relative threat of eachintruder by using various symbols and colors.

WHAT

IS THE

TCAS IISYSTEM?

Complementing the displays,TCAS II provides appro-priate synthesized voice announcements.A completelist of symbols and announcements is given in theOperation section of this User’s Manual.

ATC procedures and the “see and avoid concept”willcontinue to be the primary means of ensuring aircraftseparation.However, if communication is lost withATC,TCAS II adds a significant backup for collisionavoidance.

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SECTION 2Operation

TCAS II Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

TCAS II Traffic Display Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9

Off Scale Traffic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13

The RA/VSI Instrument . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14

The TA/VSI Instrument . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15

How To Fly Typical TCAS II Commands – Change 6.04a . . . . . . . . . . . . . . . . .15

How To Fly Typical TCAS II Commands – Change 7.0 . . . . . . . . . . . . . . . . . .24

Audio Announcements – Change 6.04a . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34

Audio Announcements – Change 7.0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36


The TCAS II System:• Is compatible with and independent of the

ATC System

• Determines if a threat exists

• Provides display and audio announcement tothe crew

– Position information displayed on CRTand/or TA/VSI

– Vertical guidance displayed on VSI

– Synthesized voice

• Calculates appropriate vertical evasive maneuver

• Coordinates maneuvers of two or more TCAS IIequipped aircraft via Mode S transponder communi-cation between aircraft.

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TCAS IIOperation

The TCAS II system monitors the airspace sur round-ing your aircraft by interrogating the transponder ofintruding aircraft.The interrogation reply enablesTCAS II to compute the following information aboutthe intruder:

1) Range between your aircraft and the intruder.

2) Relative bearing to the intruder.

3) Altitude and vertical speed of the intruder, ifreporting altitude.

4) Closing rate between the intruder and youraircraft.

Using this data TCAS II predicts the time to,and theseparation at,the intruders closest point of approach(CPA).Should TCAS II predict that certain safeboundaries may be violated,it will issue a TrafficAdvisory (TA) to alert the crew that closing traffic isin the vicinity.

If the intruder continues to close,TCAS II will issue aResolution Advisory (RA) to obtain or maintain safevertical separation between your aircraft and theintruder.TCAS II bases the alarms on a five secondcrew reaction time to begin the separation maneuver.Increase or reversal of an RA requires a reaction intwo and one half seconds.


Two TCAS II equipped airc raft will coordinate theirresolution advisories using a Mode S transponder air-to-air data link.The coordination ensures that com-p l e m e n t a ry advisories are issued in each airc ra f t . T h ec rew should promptly but smoothly follow the advisory.Since maneuvers are coordinated, the crew should neve rm a n e u ver in the opposite direction of the advisory.

TCAS II can tra ck as many as 45 airc ra f t ,d i s p l ay upto 30 of them and can coordinate a resolution advi-s o ry for up to three intru d e rs at once.The advisori e sa re always based on the least amount of dev i a t i o nf rom the flight path while providing safe ve rt i c a ls e p a ra t i o n .

Typical TCAS IIEncounter

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TCAS IITrafficDisplaySymbols

TCAS II will display four dif ferent traffic symbols onthe Traffic Advisory displays.The symbols changeshape and color to represent increasing levels ofurgency.

The traffic symbols may also have an associated alti-tude tag which shows relative altitude in hundreds offeet,indicating whether the intruder is climbing, fly-ing level or descending.A + sign and number abovethe symbol means the intruder is above your altitude.A - sign and number beneath indicates it is belowyour altitude.A trend arrow appears when the intrud-er’s vertical rate is 500 feet per minute or greater.

If the intruder is Non-Altitude Reporting (NAR) thetraffic symbol appears without an altitude number ortrend arrow.The type of symbol selected by TCAS II isbased on the intruder location and closing rate.

If TCAS direction finding techniques fail to locate theazimuth of another aircraft,a NO BEARING messageappears on the screen.


An open white diamond indicates that an intruder’srelative altitude is greater than plus or minus 1200feet vertically or its distance is beyond 6 nm range.Itis not yet considered a threat.

This one is 1700 feet below your own altitude, climb-ing at 500 feet per minute or greater.

Non-ThreatTraffic

ProximityIntruderTraffic

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A filled white diamond indicates that the intrudingaircraft is within plus or minus 1200 feet verticallyand within 6 nm range,but is still not considered athreat.

This intruder is now 1000 feet below your aircraftand climbing.

TrafficAdvisory (TA)

A symbol change to a filled yellow circle indicatesthat the intruding aircraft is considered to be poten-tially hazardous.Depending on your altitude TCAS IIwill display a TA when the time to CPA is between 20and 48 seconds.

Here the intruder is 900 feet below your aircraft,climbing at 500 feet per minute or greater.A voiceannouncement is heard in the cockpit,advising,

“Traffic, Traffic”Under normal conditions a TA will precede an RA by10 to 15 seconds. The crew should attempt to gainvisual contact with the intruder and be prepared tomaneuver should an RA be sounded 10 to 15 secondslater. The crew should take no evasive actions basedsolely on the TCAS II display.


A solid red square indicates that the intruding aircraftis projected to be a collision threat.TCAS II calculatesthat the intruder has reached the point where aResolution Advisory is necessary.The time to closestapproach with the intruder is now between 15 and35 seconds depending on your altitude.the symbolappears together with an appropriate audio warningand a vertical maneuver indication on the RA/VSI.Voice announcements are listed later in this section.

This aircraft is now 600 feet below your altitude andstill climbing.A synthesized voice announces a verti-cal maneuver command,such as,

“Climb, Climb, Climb.”(Change 6.04a)

or

“Climb, Climb.”(Change 7.0)

The pilot should smoothly but firmly initiate anyrequired vertical maneuver within 5 seconds from thetime the RA is posted, using pitch cues or the VerticalSpeed Indicator as appropriate.

An intruder must be reporting altitude in order to gen-

ResolutionAdvisory(RA)

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Off ScaleTraffic

erate an RA. Therefore, the RA symbol will always havean altitude tag.

The presence of TA or RA aircraft that are beyond theselected display range is indicated by one half of thetraffic symbol at the edge of the screen.The positionof the half-symbol represents the bearing of theintruder.


TA AND RA TRAFFICOFF SCALE, TCAS

MODE FORMAT.

SAME TRAFFIC ON10 MILE RANGE,WEATHER MODE

FORMAT.

TCAS II guidance is incorporated into the verticalspeed indicator.Two rows of colored lights,one greenand one red,are located around the vertical speedscale.TCAS II uses the lights to indicate whether toclimb,descend or remain level.The lights are OFFunless an active Resolution Advisory is in progress.

Resolution Advisories are grouped as CorrectiveAdvisories or Preventive Advisories.CorrectiveAdvisories require a positive action by the crewaccompanied by a green arc on the RA/VSI showing“Fly To”guidance. Preventive Advisories require thatNO action be taken to alter the flight path of the air-craft.

When TCAS issues an RA,certain segments in the rowof red lights will be turned on.Segments in the rowof green lights will be on when the pilot is requiredto actively maneuver the aircraft to satisfy the resolu-tion advisory. For safe separation from the intruder,the pilot should maneuver the aircraft within the ver-tical speeds represented by the green lights.Verticalspeeds within the red area must be avoided.

An RA may be presented on the VSI requiring avoid-ance of two or more threat aircraft simultaneously.For example a “do not descend”indication may be vis-ible at the same time a “limit climb rate”indicationappears because of threat aircraft above and belowyour own aircraft.

The RA/VSIInstrument

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The TA/VSIInstrument

The TA/VSI combines the plan position of intrudingaircraft and TCAS II guidance on the vertical speedinstrument.

A pointer and circular vertical speed scale indicateaircraft vertical rate.Resolution Advisories are shownas red and green bands outside of the scale.The cen-ter of the display presents intruding traffic.Refer toSection 3 for a detailed description of the TA/VSI.

The Resolution Advisory is incorporated into theVertical Speed Indicator. By illuminating red andgreen light bands around the dial,“Fly-To”and “Fly-Away-From”commands are displayed coinciding withthe required vertical rate. Maneuver the aircraftpromptly and smoothly in response to the ResolutionAdvisory.

Some of the typical Resolution Advisories shown onthe RA/VSI will require a maneuver by the crewwhile others will warn against maneuvering.A typicalTCAS II maneuver requires crew response within 5seconds and G-forces of ± .25 G.This force is similarto that experienced when initiating an enroute climbor descent. Because of this G-force requirement, theresponse to the RA cannot be flown using the autopi-lot. The autopilot must be disconnected prior toresponding to the RA.

The following diagrams illustrate typical TCAS IIencounters showing intruder traffic on a display andthe corresponding resolution on the RA/VSI.


How to Fly TypicalTCAS IICommands –Change6.04a

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Indicationsand VoiceAnnounce-ments

Change 6.04a

Comments

“Climb, Climb, Climb.”

Situation:The intruder is ahead at 12:00 o’clock,200 feetbelow your altitude.

Crew Response:Promptly and smoothly establish a climb rate of 1500feet per minute.



Change 6.04a

Comments

“Monitor Vertical Speed,

Monitor Vertical Speed.”

Situation:One intruder is ahead at 12:00 o’clock,500 feetabove your altitude. Another is 500 feet below youraltitude.

Crew Response:Remain in level flight.Do not climb or descend.

“Monitor Vertical Speed.”

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Change 6.04a

Comments Situation:The intruder is ahead at 12:00 o’clock,500 feetbelow your altitude and f lying level.

Crew Response:Do not descend.

“Traffic, Traffic”


Situation:The intruder is ahead at 12:00 o’clock,beyond 5miles,200 feet below your altitude.

Crew Response:You do not maneuver on the Traffic Advisory symbol.Attempt to visually acquire the intruder and be pre-pared to maneuver if the TA changes to an RA.


Change 6.04a

Comments

“Monitor Vertical Speed.”

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Change 6.04a

Comments Situation:The intruder is ahead at 12:00 o’clock,400 feet aboveyour altitude You are already climbing at 2000 feetper minute.

Crew Response:Maintain climb at present rate.

Crew Response:Promptly and smoothly establish a descent rate of1500 feet per minute.


Situation:One intruder is ahead at 12:00 o’clock,200 feetabove your altitude.

“Descend, Descend,

Descend.”


Change 6.04a

Comments

“Climb; Climb Now,

Climb, Climb Now.”

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Situation:The intruder is ahead and above and has changedfrom level flight to a rapid descent after TCAS issueda descend RA. TCAS is now changing that to a climb.

Crew Response:You are expected to initiate the change from adescent to a climb maneuver within 2.5 seconds withan increase in G-force to .35 Gs.


Change 6.04a

Comments

“Clear of Conflict”


Situation:The intruder has passed behind and is now 600 feetbelow your altitude. It is no longer a threat.

Crew Response:Return promptly to the previous ATC clearance.


Change 6.04a

Comments

The Resolution Advisory is incorporated into theVertical Speed Indicator. By illuminating green andred light bands around the dial,“Fly-To”and “Fly-Away-From”commands are displayed coinciding with thevertical rate required to comply with the ResolutionAdvisory. Maneuver the aircraft promptly and smoothlyin response to the Resolution Advisory.

Some of the typical Resolution Advisories shown onthe RA/VSI will require a maneuver by the crewwhile others will warn against maneuvering.A typicalTCAS II maneuver requires crew response to the ini -tial RA within 5 seconds and G-forces of ± .25 G.Thisforce is similar to that experienced when initiating anenroute climb or descent. Because of this G-forcerequirement, the response to the RA cannot be flownusing the autopilot. The autopilot must be disconnect-ed prior to responding to the RA.When the initial RAis changed,the crew must respond within 2 1/2 sec-onds.

The following diagrams illustrate typical TCAS IIencounters showing intruder traffic on a display andthe corresponding resolution on the RA/VSI.

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How to Fly TypicalTCAS IICommands –

Change 7.0


“Climb, Climb.”

Situation:The intruder is ahead at 12:00 o’clock,200 feetbelow your altitude and f lying level.

Crew Response:Promptly and smoothly establish a climb rate of 1500feet per minute.


Change 7.0

Comments

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“Adjust Vertical Speed,

Adjust.”


Change 7.0

Comments Situation:The previous intruder is now 500 feet below youraltitude while still at 12:00 o’clock and flying levelafter your having followed the CLIMB RA.

Crew Response:Promptly and smoothly level the aircraft.


“Maintain Vertical Speed,

Maintain.”

Situation:One intruder is ahead at 12:00 o’clock,500 feetabove your altitude.Another is at 500 feet below youraltitude. Both are f lying level.

Crew Response:Remain in level flight.Do not climb or descend.


Change 7.0

Comments

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“Monitor Vertical Speed,

Monitor Vertical Speed”Indicationsand VoiceAnnounce-ments

Change 7.0

Comments Situation:The intruder is ahead at 12:00 o’clock,500 feetbelow your altitude and f lying level.

Crew Response:Do not descend. Maintain level flight.


“Traffic, Traffic”

Situation:The intruder is ahead at 12:00 o’clock,beyond 5miles,200 feet below your altitude.

Crew Response:You do not maneuver on the Traffic Advisory symbol.Attempt to visually acquire the intruder and be pre-pared to maneuver if the TA changes to an RA.


Change 7.0

Comments

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“Maintain Vertical Speed,

Crossing Maintain”


Change 7.0

Comments Situation:The intruder is ahead at 12:00 o’clock,400 feet aboveyour altitude and f lying level. You are already climb-ing at 2000 feet per minute.

Crew Response:Maintain climb at present rate.


“Descend, Descend.”Indicationsand VoiceAnnounce-ments

Change 7.0

Comments Situation:One intruder is ahead at 12:00 o’clock,200 feetabove your altitude and f lying level.

Crew Response:Promptly and smoothly establish a descent rate of1500 feet per minute.

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“Climb, Climb Now,

Climb, Climb Now.”


Change 7.0

Comments

Crew Response:You are expected to initiate the change from adescent to a climb maneuver within 2.5 secondsusing an acceleration of .35 Gs.

Situation:The intruder is ahead and above and has changedfrom level flight to a rapid descent after TCAS issueda descend RA. TCAS is now changing that to a climb.


“Clear of Conflict”Indicationsand VoiceAnnounce-ments

Change 7.0

Comments Situation:The intruder has passed behind and is now 600 feetbelow your altitude. It is no longer a threat.

Crew Response:Return promptly to the previous ATC clearance.

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Recoveryafter Clearof Conflict

AudioAnnounce-ments –change 6.04a

AudioMessages

Change 6.04a

• If initially in level flight,promptly but smoothlyreturn to the previously assigned altitude unlessotherwise directed by ATC.

• If climbing or descending resume the plannedclimb or descent after the intruder has passed byunless otherwise directed by ATC.

Synthesized voice announcements are issued by TCASII over the aircraft audio system.The following tableslist all of the Resolution Advisories,audio messagesand advisories in the TCAS II vocabulary.

CONDITION ADVISORY MESSAGE

TRAFFIC ADVISORY “Traffic,Traffic”*

RA CLEARED “Clear of Conflict”

SELF TEST PASSED “TCAS System Test OK”

SELF TEST FAILED “TCAS System Test Fail”*

“Traffic”is spoken once if a second TA appears.


List ofResolutionAdvisories

Change 6.04a

ResolutionAdvisoriesandSynthesizedVoiceAnnounce-ments

Change 6.04a

RA CATEGORY CORRECTIVE PREVENTIVE

CLIMB “Climb, Climb,Climb”

“Monitor VerticalSpeed, MonitorVertical Speed”

DESCENT “Descend, Descend,Descend”

“Monitor VerticalSpeed.* MonitorVertical Speed”

CROSSOVERCLIMB

“Climb, CrossingClimb, Climb,Crossing Climb”

“Monitor VerticalSpeed. MonitorVertical Speed”

CROSSOVER DECENT


“Descend, CrossingDescend. Descend,Crossing Descend”

VERTICAL SPEEDR E S T R I C T E D( C L I M B I N G )

“Reduce Climb,Reduce Climb”



VERTICAL SPPEDRESTRICTED(DESCENDING)

“Reduce DescentReduce Descent”

*”Monitor Vertical Speed”is spoken once if downgrad-ed froma previous corrective advisory.

The following Resolution Advisories are changes fromthose previously issued and require two and one halfseconds response time and up to .35 G.

CHANGE FROMCLIMB TODESCENT

CHANGE FROMDESCENT TOCLIMB

INCREASECLIMB RATE

INCREASECLIMB RATE

“Descend, DescendNOW. Descend, Descend NOW”

“Climb, Climb NOW.Climb, Climb NOW”

“Increase Climb,Increase Climb”

“Increase Descent,Increase Descent”

(N/A)

(N/A)

(N/A)

(N/A)

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AudioAnnounce-ments –change 7.0

AudioMessages

change 7.0

Synthesized voice announcements are issued by TCASII over the aircraft audio system.The following tableslist all of the Resolution Advisories,audio messagesand advisories in the TCAS II vocabulary.

CONDITION ADVISORY MESSAGE

TRAFFIC ADVISORY “Traffic,Traffic”*

RA CLEARED “Clear of Conflict”

SELF TEST PASSED “TCAS System Test OK”

SELF TEST FAILED “TCAS System Test Fail”*

“Traffic”is spoken once if a second TA appears.


ResolutionAdvisoriesandSynthesizedVoiceAnnounce-ments

change 7.0

List ofResolutionAdvisories

change 7.0

RESOLUTION ADVISORY AUDIO MESSAGE

CLIMB

DESCENT

“Climb, Climb”

“Descend, Descend”

CROSSOVERCLIMB

CROSSOVERDESCENT

“Climb, Crossing Climb-Climb, Crossing Climb”

“Descend, Crossing Descend-Descend, Crossing Descend”

VERTICAL SPEED RESTRICTED(CLIMBING OR DESCENDING)

“Adjust Vertical Speed, Adjust”

ANY WEAKENING ORSOFTENING OF AN RA

“Adjust Vertical Speed”

PREVENTATIVE ADVISORY “Monitor Vertical Speed”

MAINTAIN EXISTINGVERTICAL SPEED

“Maintain Vertical Speed,Maintain”

MAINTAIN EXISTING VERTICALSPEED WHILE CROSSINGTHREAT’S ALTITUDE

“Maintain Vertical Speed,Crossing Maintain”

CHANGE FROM CLIMB TODESCENT

CHANGE FROM DESCENT TOCLIMB

INCREASE CLIMB RATE

INCREASE DESCENT RATE

“Descend, Descend NOW -Descend, Descend NOW”

“Climb, Climb NOW - Climb, Climb NOW”

“Increase Climb - Increase Climb”

“Increase Descent - Increase Descent”

The following Resolution Advisories are changes fromthose previously issued and require two and one halfseconds response time and up to .35 G.

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SECTION 3Controls and Displays

Transponder/TCAS Control Unit;CTA-81A,CTA-81B,CTA-81C . . . . . . . . . . . 40

Weather Radar Indicators;RDR-4,RDR-1F, RDR-1E . . . . . . . . . . . . . . . . . . . . . 45

Weather Modes Message Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51

TCAS Mode Message Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

Fault Message Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

Fault Annunciations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

ITA-81A Dedicated TCAS Traffic Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

IVA-81B RA/VSI Resolution Advisory/Vertical Speed Indicator . . . . . . . . . . . . 56

IVA-81A/IVA-81D TA/VSI Traffic Advisory/Vertical Speed Indicator . . . . . . . . 57

Typical TA/VSI Scenarios . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

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CTA-81A DUAL MODE S/TCAS CONTROL UNITCTA-81C SINGLE MODE S/TCAS CONTROL UNIT

(CTA-81A SHOWN)

Transponder/TCASControlUnit; CTA-81A,CTA-81B,CTA-81C

CTA-81A,CTA-81B,CTA-81CControlsand Displays

CTA-81B MODE S/ATCRBS/TCASCONTROL UNIT

The CTA-81 ( ) Control Unit is the master controlfor both the TCAS system and transponder.The CTA-81A controls two Mode S transponders.The CTA-81Bcontrols one Mode S transponder and one ATCRBStransponder.The CTA-81C controls one Mode Stransponder.

NOTE: Controls vary depending on CTA-81 ( ) con-figuration installed.Control functions same as typicalunit shown.


The Display Window Displays ATC codeselection and whether transponder No.1 or No.2 is active.The R blinks indicat-ing interrogation reply of ATCRBStransponder only.

ATC 1-2 selects the active transponder.The other unit is placed in standby.

ALT ON/OFF turns altitude source ONor OFF.

Concentric knobs select ATC code incode window.

The ATC FAIL Lamp indicates failure ofthe selected transponder.

ATC IDENT initiates IDENT feature forATC.

ALT 1-2 (CTA-81A) or ALT SOURCE1/OFF/2 (CTA-81B) selects one of twoaltitude sources Air Data Computer No.1 or No.2.OFF position disables alti-tude squawk.

(Pushbutton)

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The TCAS RANGE Selector selects theTraffic Advisory display range in nauticalmiles.

The FL pushbutton (Center of TCASRange Knob) replaces intruder’s relativealtitude with absolute altitude in flightlevel format for 15 seconds.During thisperiod your own altitude, expressed asflight level,is displayed.After 15 secondsflight level reverts back to relative alti-tude.

The FL function is inhibited below18,000 feet MSL unless barometric cor-rected altitude is available from an airdata computer. In this case the FL func-tion is available at any altitude.

If FL is selected while inhibited,“FL—-”will replace own flight level.

A/B (Above/Below) toggle switchselects altitude display limits.Three lev-els to choose from.

ABOVE (Climb phase) 9000 feet above;2700 feet below –Change 7.0

8700 feet above;2700 feet below –Change 6.04a

NORMAL (Enroute phase) 2700 feet above;2700 feet below.

BELOW (Descent phase) 2700 feet above;9000 feet below –Change 7.0


(Pushbutton)


FunctionSelectorCTA-81A/CControlUnit Only(selectsoperatingmode)

Moving the spring loaded knob to TEST position forone second initiates a comprehensive self test lastingapproximately twelve seconds.Refer to the Test sec-tion in the Appendix for a detailed description of testfunctions.

STBY places Mode S transponder and TCAS system instandby.

ALT OFF activates transponder without altitudereporting.TCAS system in standby.

ALT ON activates transponder with altitude report-ing.TCAS system in standby.

TA Traffic Advisory mode.Presents traffic location onTA display but does not issue Resolution Advisories.TA mode annunciation appears on displays.Activatestransponder and altitude reporting.

TA/RA Traffic Advisory and Resolution Advisorymode.Presents traffic location on displays and issuesaudio and visual Resolution Advisories for trafficdetermined to be a threat.TA/RA mode annunciationappears on PPI or ITA-81A displays.Activatestransponder and altitude reporting.

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There are no TCAS functions on the ATC 2 (3 mostclockwise) positions.

The left ATC 1 TEST position (CCW) tests the ModeS transponder and the TCAS system.The right ATC 2TEST position (CW) tests the ATCRBS transponder.

FunctionSelectorCTA-81BControlUnit Only(selectsoperatingmode)

Moving the spring loaded knob to either TEST posi -tion initiates a self test in the respective unit.Refer tothe Test section in the Appendix for a detaileddescription of test functions.

Selection of either STBY position places bothtransponders and TCAS II system in standby.

ATC 1 ON activates the Mode S transponder.TCAS instandby.

ATC 2 ON activates the ATCRBS transponder.TCAS instandby.

TA Traffic Advisory mode.Presents traffic location ondisplays but does not issue Resolution Advisories.TAmode annunciation appears on displays.Mode Stransponder activated with altitude reporting

TA / R A Tra ffic A d v i s o ry and Resolution A d v i s o ry mode.P resents tra ffic location on displays and issues audioand visual Resolution A d v i s o ries for tra ffic determ i n e dto be a thre a t .TA/RA mode annunciation appears onPPI or ITA-81A display s . Mode S transponder activa t e dwith altitude re p o rt i n g .


WeatherRadarIndicators;RDR-4,RDR-1F,RDR-1E

RDR-4,(PPI-4B)

46ACS-5059 • Rev 5 - 02/2000


RDR-1F,(PPI-1T)

RDR-1E,(PPI-1U)


(Pushbutton)

PPI-1T,PPI-1U and PPI-4BIndicatorControls

NOTE: Control arrangement varies depending on PPIradar configuration installed.TCAS control functionsare the same as typical unit shown.

TCAS cycles through display modes;WX/TCAS Pop-Up,WX/TCAS Overlay,and TCAS Only.

At Power-Up the screen initially displaysthe TCAS Only mode.Pressing the TCASbutton once changes the display to WXOnly mode.

Pressing again changes the display toWX/TCAS Overlay. (TCAS traffic is over-layed on weather.)

Pressing again changes the display backto the TCAS Only mode.

In WX/TCAS Pop-Up mode,the displayshows the selected radar function.When a TA or RA occurs,the displayautomatically switches to the TCAS Onlymode.The range changes to the previ-ously selected TCAS range.

Pressing the TCAS button once after aPop-Up event occurs returns the displayto previous weather.The display willonce again be interrupted if another TAor RA Pop-Up penetrates the protectedrange of your aircraft.When the traffic isno longer a threat,the screen automati-cally reverts to displaying weather.

48ACS-5059 • Rev 5 - 02/2000


(Pushbutton)

(Pushbutton)

MSG. The message pushbutton activatesthe ACARS mode.During ACARS displaya TCAS Pop-Up event replaces theACARS page with TCAS Only.When thetraffic is no longer a threat the screenautomatically reverts back to displayingACARS.

Pressing the MSG button once duringthe event reverts the display back to theprevious ACARS display page.The dis-play will once again be interrupted ifanother TA or RA event occurs.

This Function Selector turns on theweather radar system and selects theoperating mode; TCAS selects a TCASonly display, WXR/TCAS selects weatherwith TCAS overlay display, and WXRselects a weather only display.

Pressing the FL pushbutton replacesintruders relative altitude with flightlevel.During this period your own flightlevel is displayed.Pressing the buttonagain changes the display back to rela -tive altitude.

The FL function is inhibited below18,000’MSL unless barometric altimetersettings are available from the air datacomputer.


PPI-1T,PPI-1U and PPI-4BIndicatorControls(cont’d)

The Range Selector selects range to bedisplayed.In the position labeled NOWXR, the display shows TCAS trafficonly (no radar).

WARNING: The RDR-1E/ED and RDR-1Ftransmitters continue to radiate in the 5and 10 mile NO WXR ranges if an activemode is selected on the radar controlpanel (any mode except TEST).Refer tothe appropriate Weather RadarOperating Manual for Cautions andLimitations prescribed by FAA AdvisoryCircular 20-68B.

The A/B (Above/Below) pushbutton ortoggle switch selects altitude displaylimits.Three levels to choose from:

ABOVE (Climb phase) 9000 feet above;2700 feet below –Change 7.0



BELOW (Descent phase) 2700 feet above;9000 feet below –Change 7.0


50ACS-5059 • Rev 5 - 02/2000


(Pushbutton)

The Function Selector turns on theweather radar system and selects oper-ating mode;either a TCAS mode or aWeather mode.

WEATHER Modes TCAS ModeThe Weather modes; WX, TURBand MAP, show the display ori-gin at the bottom center of thescreen. The weather and TCASviews are forward. The displayshows radar functions withTCAS overlay depending on theselection by the TCASAUTOpushbutton. At Power-Up the screen initiallydisplays the WX/TCAS overlaymode. Mode annunciation is theTCAS operational mode.

In the TCAS position TCAS ONLYfunction is selected. No Weatheris displayed. The airplane sym-bol appears in the lower 1/3 ofthe screen displaying trafficahead of and behind your air -craft.At Power-Up the screen initiallydisplays all TCAS traffic only.Mode annunciation is the TCASoperational mode.

WEATHER Modes TCAS Mode

Pressing the button changes themode to TCAS Pop-Up whichdisplays WX only until a TA orRA intruder appears. Annunciation changes to TAAUTO or TA/RA AUTO. WhenTA/RA traffic enters the protect-ed area all TCAS traffic is shownover weather. When the intruderis no longer a threat the screenautomatically reverts back todisplaying weather only.Pressing the button once morechanges the display back toWX/TCAS overlay mode.

Pressing the button oncechanges to TCAS Pop-Up mode.TCAS AUTO is annunciated.In Pop-Up mode the screenclears and remains blank untilTA or RA traffic appears. Thenall TCAS traffic is displayed.The screen automatically clearswhen the intruder is no longer athreat.Pressing the button once morechanges the display back to Full-Time display of all traffic.


WeatherModesMessageFormat

TCAS STBY (Blue) — TCAS system in standby

TEST (Blue) — TCAS system in TEST

TA/RA (Blue) — TA/RA Mode

TA/RA AUTO (Blue) — TA/RA Pop-Up Mode

TA ONLY (Blue) — TA Only Mode

TA AUTO (Blue) — TA Only Pop-Up Mode

TD FAIL (Yellow) — Indicator Failure

NO TCAS (Blue) — TCAS not operational.Place Function Selector to TCAS for a list of faults.

TCAS FAIL (Yellow) — Failures include:TCAS Processor or Top or Bottom TCAS Ant-enna.Place Function Selector to TCAS for a list of faults.

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TCAS ModeMessageFormat

TCAS STBY (Blue) — TCAS system in standby

TEST (Blue) — TCAS system in TEST

TA/RA (Blue) — TA/RA Mode

TA/RA AUTO (Blue) — TA/RA Pop-Up Mode

TA ONLY (Blue) — TA Only Mode

TA AUTO (Blue) — TA Only Pop-Up Mode

TD FAIL (Yellow) — Indicator Failure


FaultMessageFormat

FaultAnnuncia-tions

NOTE: If a fault occurs while in the WX function(TCAS FAIL annunciated), switch to the TCAS func-tion for a list of faults.

If already in the TCAS function, faults come up auto-matically.

TCAS PROCESSOR

UPPER ANTENNA

LOWER ANTENNA

RADIO ALT #1

RADIO ALT #2

RADIO ALT #1 and #2

#1 XPNDR DATA BUS

#2 XPNDR DATA BUS

TRAFFIC DISPLAY

RA DISPLAY #1

RA DISPLAY #2

RA DISPLAY #1 and #2

SELECTED XPNDR

XPNDR TOP ANT

XPNDR LOWER ANT

XPNDR TCAS DATA

XPNDR CONTROL DATA

XPNDR ALT DATA #1 and #2

#1 XPNDR ALT DATA

#2 XPNDR ALT DATA

ATTITUDE

HEADING

54ACS-5059 • Rev 5 - 02/2000


ITA-81ADedicatedTCAS TrafficDisplay


ITA-81ADedicatedTCAS TrafficDisplayControls

Pushbutton Range Selectors select range tobe displayed.

TCAS/AUTO Pushbutton:At Power-Up the screen initially displays all TCAS traffic.Pressing the button alternates betweenFull-Time and TCAS Pop-Up modes.

When in Pop-Up mode the screen clearsand remains blank until TA or RA trafficappears.Then all TCAS traffic is dis-played.TCAS AUTO is annunciated.Thescreen automatically clears when theintruder is no longer a threat.Pressing the TCAS/AUTO button when no TCAStraffic is displayed returns the display tothe Full-Time mode.

Pushbutton controls select vertical displaylimits.

ABOVE (Climb phase) 9000 feet above;2700 feet below – Change 7.0

8700 feet above;2700 feet below – Change 6.04a


BELOW (Descent phase) 2700 feet above;9000 feet below – Change 7.0

2700 feet above;8700 feet below – Change 6.04a

Adjusts display brightness.

56ACS-5059 • Rev 5 - 02/2000


IVA-81BRA/VSIResolutionAdvisory/VerticalSpeedIndicator

VSI Flag (Amber)

(Not capable of displaying

vertical speed)

- RA/VSI Failure

- Power Failure or

- VS Source Failure

RA OFF (White)

TCAS Flag

- TCAS is in STBY.

- TCAS in TA ONLY mode.

- Power loss in the

RA/VSI.

- System operating in

automatic TA ONLY mode.

TCAS (Amber)

Both Flags disappear during normal operation.

The RA OFF/TCAS flag may appear independently

of the VSI flag. Whenever the VSI flag appears

the RA OFF flag will also appear.

- TCAS Failure

Resolution Advisory

“Fly-Away-From”

Command Arc

(Red)

Resolution Advisory

“Fly-To” Command

Arc (Green)

Ambient Light

Sensor

Vertical Speed

Pointer

Two rows of colored lights,one red and one green,are located around the vertical speed scale.TheRA/VSI indicates whether to climb,descend, remainlevel or otherwise change the vertical speed by light-ing segments of these rows.The required verticalmaneuver keeps the pointer out of the red,and/orinto the green areas.


IVA-81A/IVA-81D

TA/VSITrafficAdvisory/VerticalSpeedIndicator

Vertical Speed

Pointer

Resolution

Advisory

“Fly-Away-

From”

Command Arc

(Red)

Intruders

Own

Aircraft

Symbol

Maximum

Range

Border

Resolution

Advisory

“Fly-To”

Command Arc

(Green)

TA Select

Pushbutton–

Traffic Select

or Switchable

as wired

during

installation

Range Pushbuttons -

The following are range selec-

tion possibilities and are con-

figured during installation:

• 3, 5, 10 and 15 NM

• 3, 5, 10, 20 and 40 NM

• 5, 10, 20 and 40 NM

• 3, 5, 10, 20 and 40 NM

Not all unit versions suppor t

all listed range selections.

Off Scale

Traffic

2 Mile

Range

Ring

Brightness

Control

The TA/VSI combines the vertical speed instrumentwith the TA and RA display functions.Red and greenbands around the circumference of the screen giveRA information.Traffic location is presented on theface of the display inside of the vertical speed scale.

58ACS-5059 • Rev 5 - 02/2000


ConfiguredforSwitchable

Configuredfor TASelect

Versions of the IVA-81A/IVA-81D which have a TASelect pushbutton (TA SEL) on the bezel can be con-figured to operate in either the TRAFFIC SELECTmode or the SWITCHABLE mode.The following aredescriptions of each mode of operation:

When no TA or RA traf fic is present,the IVA-81A/IVA-81D operates in the Vertical Speed Indicator modeonly, with no TCAS Traffic Display overlay. Pressing TASelect will have no effect when no TA or RA traffic isin the area.When a TA or RA intruder is detected,theunit automatically changes to the Traffic Displaymode with a Vertical Speed Indicator overlay.With anintruder present,pressing TA Select will revert thedisplay back to VSI mode only. The unit automaticallyreverts back to the Vertical Speed Indicator modewhen threat traffic is no longer present.The presenceof a new TA or RA intruder will initiate a repeat ofthis cycle of operation.

The IVA-81A/IVA-81D operates in either the TrafficDisplay mode or the Vertical Speed indicator mode,regardless of whether there is threat traf fic present.The display formats are selected manually by press-ing TA Select.When a TA or RA intruder is detected,and if the display format has not been previouslymanually selected,the unit automatically changes tothe Traffic Display mode with a Vertical SpeedIndicator overlay.Again,pressing TA Select will alter-nate between the two formats.The unit will not auto-matically revert back to the Vertical Speed only modewhen threat traffic is no longer present.The presenceof a new TA or RA intruder will initiate a repeat ofthis cycle of operation if the display format wasVertical Speed only format.


DisplayMessageLocations

(Blue) TCAS system in standby

(Blank)

(Yellow)

(Blue/Yellow - when active TA)

(Yellow) TCAS system failure

TCAS STBY (Blue)

TA/RA (Blank)

TEST (Yellow)

TA ONLY (Blue)

TCAS (Yellow)

NO TCAS

TA/RA

TEST

TA ONLY

NO TCAS

TCAS Mode/Failure

Standard Optional

Display Message Locations

60ACS-5059 • Rev 5 - 02/2000


TypicalTA/VSIScenarios


62ACS-5059 • Rev 5 - 02/2000



SECTION 4System Considerations

Warnings and Limitations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64

Cautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .67

Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .68

64ACS-5059 • Rev 5 - 02/2000


Warnings and Limitations specific to Change 7.0 orChange 6.04a are identified as such.The capability ofTCAS II is dependent upon the type of transponderin the intruding aircraft:

• The intruding aircraft must be equipped witha properly operating transponder for normalTCAS operation.TCAS is unable to detect anyaircraft without an operating transponder.

• If the intruder is Non-Altitude Reporting(NAR),TCAS will display only the range andbearing.It can issue a Traffic Advisory basedon distance and direction of flight but will notgenerate a Resolution Advisory. TCAS assumesNon-Altitude Reporting (NAR) traffic is at thesame altitude as your own aircraft.

TCAS does not display NAR traffic above 14,500 feet.

A TCAS II Resolution Advisory is based on the expec-tation that the crew will comply within 5 seconds.Any modification to the initial RA,including anincrease or reversal to an RA, requires two and onehalf seconds reaction time.

The TCAS II processor is programmed with the spe-cific aircraft operating limitations,i.e.,maximum alti-tude at which the aircraft can climb at 1500 feet perminute.Climb or Increase Climb RAs are thereforeinhibited when the RA maneuver cannot be complet-ed safely due to lack of aircraft performance capabili-ty.These performance limits are included as part ofthe aircraft wiring.See the AFM (Airplane FlightManual) for the specific performance limitations foryour aircraft.

Wiring options for TCAS also include the following:

• TCAS II can be wired to display all traffic fulltime or all traffic only as a result of the pres-ence of a TA or an RA.

• The TCAS display may have pilot selectablerange or may be a fixed range controlled by

WarningsandLimitations


the aircraft wiring.

• The TCAS II system can be automatically placed instandby when the aircraft is on the ground.

• The IVA-81A/IVA-81D can be wired to clear the dis-play automatically after a TA or RA passes,or bypressing the TA SEL button,if applicable.

• The manually initiated TCAS test procedure can beinhibited in flight.However, this does not inhibitthe transponder self test and TCAS will be placed inSTBY during transponder Self-Test for approximate-ly 5 sec.

• The aircraft Master Lamp Test Switch can be wiredto control the TA/VSI and RA/VSI sequential lamptest.

• TCAS can be wired to inhibit display of Traffic onthe ground when your own aircraft is below 1700±50 feet AGL.If configured this way, aircraft on theground disappear as you descend through 1650feet and reappear on the traffic display as youclimb above 1750 feet.TCAS II designates “On-Ground”traffic by comparing own aircraft radioaltitude and pressure altitude.Any intruder estimat-ed by TCAS to be within 380 feet of the grounddescending or 400 feet ascending will be catego-rized “On-Ground.” If not configured this way, all“On-Ground”intruders are displayed as non-threattraffic (open white diamond).(Change 6.04a)

TCAS II does not display traf fic on the ground.(Change 7.0)

In general,if the intruder is within 380 ±20 feet of theground it will not be displayed. When another aircraftlands,it may take approximately 20 seconds for TCAS II todetermine that it has done so.(Change 7.0)

When TCAS II is on the ground,it will display existingtracks down to 150 feet of the ground. Again,it may take20 seconds for the system to determine that the aircrafthas landed.(Change 7.0)

66ACS-5059 • Rev 5 - 02/2000


Refer to the Airplane Flight Manual for the specific oper-ational features of your particular TCAS installation.

Increase Descent Resolution Advisories are inhibitedbelow 1450 feet AGL.(Change 6.04a)Increase Descent Resolution Advisories are inhibitedbelow 1450 feet AGL while descending and 1650 feetAGL while ascending.(Change 7.0)

All Resolution Advisories are inhibited below 900 feetdescending or 1100 feet ascending.

All TCAS II audio warnings are inhibited below 900 feetRadio Altitude on approach and up to 1100 feet RadioAltitude on departure.(Change 6.04a)

All TCAS II audio warnings are inhibited below 400 feetRadio Altitude on approach and up to 600 feet RadioAltitude on departure.(Change 7.0)

Maneuvers based solely on the TCAS Traffic Display areprohibited by the AFM.

RAs should be followed without the autopilot orautothrottle system engaged.

TCAS II tracking range can be severely limited in hightraffic areas. This is especially true of high traffic areaswith a high density of TCAS equipped aircraft such asterminal areas and while on the ground. While on theground, range may be reduced to below 5 miles. Aftertakeoff range will increase,but may still be limited tounder 10 miles.

This tracking range limiting is required in order to com-ply with FAA regulations,to ensure that TCAS II will notinterfere with ATC ground station tracking. This shouldnot be interpreted as a system malfunction.

The RDR-1E/ED and RDR-1F radar transmitters are con-trolled from a separate Radar Control Panel.When 5 or10 mile NO WXR range is selected on the PPI-1U, thetransmitter continues to radiate if an active mode (anymode except TEST) is selected on the Radar Control


Panel.Refer to the appropriate Weather RadarOperating Manual for Cautions and Limitations as pre-scribed by FAA Advisory Circular 20-68B.

Always attempt to visually clear the airspace beforemaneuvering your aircraft in response to a TCAS advi-sory. Do not over react to a Resolution Advisory. Flyonly the vertical speed commanded. Using highervertical speeds than that shown on the RA/VSI isNOT better. Be alert and comply with modified orweakening RAs (annunciated by “Adjust VerticalSpeed,Adjust” for Change 7.0,or “Monitor VerticalSpeed” for Change 6.04a) to minimize your displace-ment from your ATC clearance.

The TCAS installation is required to be wired to giveGPWS and Wind Shear higher priority than TCAS.Incase of simultaneous audio alarms,the TCAS II systemis placed in TA ONLY mode (aural annunciations areinhibited) and the TA/VSI and RA/VSI flag will showRA OFF.

Cautions

When TCAS commands a corrective ResolutionAdvisory, sufficient time exists to perform a smoothvertical maneuver to avoid the conflict.TCAS IIexpects five second crew reaction time to initial RAs,requiring approximately .25 G. A change to the initialRA,including an increase or reversal, requires twoand one-half seconds reaction time and up to .35 G.

It is possible to see an aircraft flying the same courseand direction as your own aircraft and be in closeproximity to your aircraft, yet TCAS II may not consid-er it a threat.TCAS II calculates the closure rate of theintruder, and derives the time to the closest point ofapproach (CPA).If there is no closure rate,no adviso-ry will be issued,unless the intruder is very close(within approximately 1/4 mile).

Conversely, traffic at the same altitude very far aheadmay be shown as an RA by TCAS because of a veryrapid closure rate.

68ACS-5059 • Rev 5 - 02/2000


Notes


SECTION 5Appendix

Functional and Automatic Self Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .70

RA/VSI Flags and Test Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .72

RA/VSI and TA/VSI Lamp Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .73

Failure Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .75

Post Flight Reports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .75

Glossary of TCAS Terms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .76

70ACS-5059 • Rev 5 - 02/2000


FunctionalandAutomaticSelf Test

The Mode S transponder and TCAS Functional Testdetermines the operational status of the entire sys-tem.The test is initiated by rotating the functionselector knob on the Transponder Control Panel tothe counter-clockwise TEST position for one second.Thereafter, the test continues automatically for a peri-od of approximately twelve seconds.During the testthe TCAS II and transponder function is inhibited.When the knob is held for longer than twelve sec-onds the system remains in test until it is released.

If the weather radar indicator is OFF, warm up timefor the weather radar indicators is about 5 seconds.

During the first few seconds of the test sequence,thecontrol panel,the ITA-81A Dedicated Traffic Display,the radar indicators,the TA/VSI,and the RA/VSI exe-cute a display test.

A test pattern appearing on the dedicated display, theradar PPI and the TA/VSI allow verification of eachtype of intruder symbol.The test generates the sym-bols arranged as shown.The Traffic Advisory Displayannunciates the word TEST. If the weather radar is inthe TEST function,this pattern appears over the PPItest pattern.If in a weather function,this test appearsover weather.

Use of the self test function in flight will inhibit TCASII and transponder operation for up to 12 seconds.For this reason,the pilot should use caution wheninitiating the test in flight.

NOTE:Some installations may inhibit the activation of TCAS self-test in flight. However,TCAS will be placed in STBY whilethe Transponder is in self test for approximately 5 sec.

During the TCAS self test operation aircraft pressure alti-tude,aircraft Mode-S Address and aircraft maximum air-speed capability are not monitored.However, thesetransponder inputs are always monitored and faults report-ed while the TCAS is in one of its active modes -- TA Onlyor TA/RA. Altitude Input to the selected transponder ismonitored by the transponder but will not display a faultmessage when selecting transponder modes.


A Resolution A d v i s o ry (red square) will appear at 3o ’ cl o ck , ra n ge of 2 miles, 1000 feet below and fly i n gl eve l .

A Tra ffic A d v i s o ry (ye l l ow circle) will appear at 9o ’ cl o ck , ra n ge of 2 miles 200 feet below and cl i m b i n g .

P roximity tra ffic (solid white diamond) will appear at1 o’cl o ck , ra n ge of 3.6 miles, 200 feet ab ove descend-i n g .

N o n - T h reat tra ffic (open white diamond) will appearat 11 o’cl o ck , ra n ge of 3.6 miles, flying level 1000 fe e tab ove .

TCAS DISPLAY TEST PATTERN; TCAS FUNCTION,5 NM RANGE, DEDICATED DISPLAY AND PPI

TA/VSI TEST PATTERN; 5 NM RANGE.

72ACS-5059 • Rev 5 - 02/2000


RA/VSI Flagsand TestIndicators

During the first few seconds of the TEST the RA/VSIred and green circumference lights (theclimb/descend indicators) illuminate sequentially.TheTCAS flag is in view throughout the test period.

SEQUENTIAL LAMP TEST


After the sequential lamp test the red and greenclimb/descend lights display a fixed test commandthroughout the remainder of the system test.

RA/VSI andTA/VSI LampTests

RA/VSI LampTest

At the conclusion of a successful Self Test,a synthe-sized voice announces,

“TCAS System Test OK”

If the aircraft wiring includes a lamp test function,the RA/VSI sequential lamp test can be observed byactivating the Master Lamp Test switch.The test willcontinue as long as the switch is held in test position.

FIXED TEST COMMAND

74ACS-5059 • Rev 5 - 02/2000


TA/VSI LampTest

The TA/VSI lamp test produces an array of traffic inthe pattern shown.The climb/descend color bandsalternate between green and red,lasting for two sec-onds each.The bands are blank for a one secondinterval in between.

NOTE: The VSI function of the TA/VSI will not beobserved during the lamp test.


Should a VSI failure be detected at any time,the VSIflag will appear.

Should a failure be detected during Self Test,theaudio message says,

“TCAS System Test Fail”If the TA display is a PPI or dedicated display, theappropriate failure message will be displayed.(SeeFault Message Format in Section 3:Controls andDisplays.)

TCAS test audio is inhibited during GPWS and winds-hear test or alert.

The CTA-81B function selector is moved to the righthand test position (switch fully clockwise) to test theATCRBS transponder. During the test,segments of theTransponder Control Unit display window and theATC Fail Lamp illuminate.

If a failure of the TCAS systems has occurred, giveMaintenance as much specific information about theproblem as possible.Avoid phrases such as “TCASinop”.

Provide information in terms of fault lights lit,audioannouncements,test patterns discrepancies andscreen annunciations that indicate which unit wasobserved to have failed.

FailureConditions

Test AudioInhibit

CTA-81BClockwiseTestPosition

Post FlightReports

76ACS-5059 • Rev 5 - 02/2000


Glossary ofTCAS Terms

A b b r e v i a t i o n sa n dD e f i n i t i o n s

AFM Airplane Flight Manual.

AGL Above Ground Level.

ATC Air Traffic Control.A federally operated ground based system that manages air-craft traffic flow.

ATCRBS ATC Radar Beacon System.A groundbased secondary radar and airbornetransponder system used to monitortraffic.

Absolute Altitude above terrain.Also called RadioAltitude Altitude.Absolute altitude is received

from a radio altimeter and used by theTCAS processor to determine distanceto the surface.

Altitude Tag Data tag shown above or below threatsymbol giving the relative altitude ofthe intruder.

BITE Built In Test Equipment.A feature ofTCAS that continually monitors itself foroperational errors.

CPA Closest Point of Approach.Refers to pre-dicted point at which the intruder willbe closest to your own aircraft.

Crossover The maneuver that TCAS has deter-Climb, mined to be appropriate is a climb Crossover or descent through the altitude of the Descent threat aircraft.The crew is alerted to

the crossover maneuver by an audiomessage.


G-Force The ratio between a given load and thepull of gravity. For TCAS purposes,G-forces of an RA could reach ±.35 dur-ing an increase or reversal of the origi-nal command.

Increase An increase maneuver is a change of the Maneuver original Resolution Advisory command,

either climb or descent, requiring agreater rate.The increase maneuvercould require G-forces to reach approxi-mately ±.35.

Indicated Altitude shown on the altimeter with Altitude barometric correction setting set to the

local sea level pressure.Used by thecrew below 18,000 feet but not usedfor TCAS processing.

Intruder Any aircraft that is in the surveillancerange of TCAS.

LRU Line Replaceable Unit.A self-containedavionics component that can bereplaced in the field.

Mode A ATCRBS transponder that replies to ATCTransponder interrogations sending identification

code but without giving altitude data.

Mode C ATCRBS transponder that replies to ATCTransponder interrogations giving identification code

or encoded altitude data.

Mode S Transponder that replies to ATC interro-Transponder gations giving an ATCRBS identification

code,encoded altitude and other datafields including aircraft discrete address.

78ACS-5059 • Rev 5 - 02/2000


MOPS Minimum Operational PerformanceStandards per RTCA document DO-185.TCAS II Change 6.04a is specified byDO-185.TCAS II Change 7.0 is specifiedby DO-185A.

NAR Non-Altitude Reporting traffic.

Non-Threat An aircraft that has entered the TCAS Intruder surveillance volume at a greater dis-

tance than 6 miles or altitude greaterthan 1200 feet above or below yourown.

Pressure Indicated altitude when barometricAltitude pressure is set to 29.92”Hg (1013.15

mb).Pressure altitude is used by TCASto determine the relative altitude oftraffic.

Proximity An aircraft that is within 6 miles rangeIntruder and with 1200 feet above or below our

own aircraft but does not meet theTCAS definition of a threat.

Rad Alt Radio Altitude.Altitude received from aradio altimeter and used by TCAS todetermine distance to the surface.SeeAbsolute Altitude.

RA Resolution Advisory. An audio and visu-al indication recommending a verticalmaneuver to achieve or maintain sepa-ration from an intruding aircraft.

RA/VSI Resolution Advisory/Vertical SpeedIndicator. A flight instrument that givesstandard VSI indication plus RA climband descend requirements.


Relative The difference in altitude between twoAltitude aircraft.TCAS calculates relative altitude

as the difference between your own air-craft’s pressure altitude and the encod-ed pressure altitude of the intruder.

Reversal A reversal maneuver is a change of theManeuver original Resolution Advisory command

from a climb to a descent or vice-versa.The reversal maneuver could requireG-forces to reach approximately ±.35.

Self Test A functional test that determines equip-ment status.Self test differs from BITEperformance monitoring because it isinitiated by the crew and is not per-formed continually or automatically.

Surveillance The volume of airspace surrounding Volume your aircraft that TCAS scans for intrud-

ing traffic.The TCAS system scansapproximately 40 NM in front of and9,000 feet above and below the aircraft.The volume will automatically begin todecrease when f lying into a high densi-ty area and may be reduced to approxi-mately 15 NM in front of the aircraft.

TA Traffic Advisory.An audio and visualindication that another aircraft is poten-tial threat.A TA may become aResolution Advisory within 15 seconds.

TA/VSI Traffic Advisory/Vertical SpeedIndicator.A flight instrument that givesstandard VSI indication,plan position oflocal traffic,plus RA climb and descentrequirements.

Threat An aircraft that has satisfied TCAS threatdetection logic and thus requiring aResolution Advisory.

80ACS-5059 • Rev 5 - 02/2000


TCAS

Documents

air data computer

vertical speed

open white

spring loaded

monitor vertical

place function

function selector

4b indicator