TCAS Flashcards
What does TCAS stand for
Traffic alert and avoidance system
What does TCAS do
Alerts the crew to other aircraft in close proximity
Advanced systems can command an escape manoeuvre to avoid collision
Interrogates transponders from other aircraft
Independent of ground based control
Where is TCAS traffic displayed
ND and PFD
What does a clear diamond shape represent in TCAS
Other traffic more then 6nm or +/- 1200ft
What does a filler diamond represent for TCAS
Proximate traffic within 6nm AND 1200ft
Or
6nm with no alt data
What does a yellow circle represent for TCAS
Traffic advisory
What does a red square represent in TCAS
Resolution advisory
What do the arrows next to the symbol for TCAS represent
Climb or descend by more then 500ft / min
What is a TCAS traffic advisory
Warning of potentially conflicting traffic
Displayed as a amber solid circle
Aural warning “traffic traffic”
Provides no escape command as crew must visually locate traffic
Within 20-48 seconds of closest point of approach (CPA)
What is a resolution advisory
Escape manoeuvre in vertical plane
Within 15-35 seconds of CPA
Must be followed
Solid red square
When can a traffic resolution advisory not be given in TCAS when both aircraft have transponders
If one is more a only
In TCAS and both aircraft are equipped with mode S how is escape actions decided
Datalink between aircraft to coordinate the RA
What is a corrective advisory (RA) TCAS
A manoeuvre is necessary to avoid a possible collision
What is a preventative advisory TCAS
Current flight path maintenance is require to avoid a possible collision
TCAS aircraft equipment
TCAS computer (transmitter / receiver unit)
2 directional antenna, one on top one on bottom
Mode s transponder
TCAS data inputs
Radio alt = inhibits RAs close to ground
ADC + altitude = supply pressure alt data
If TCAS can’t determine relative bearing
Text message shown on EVIS or ND
What is the normal operating range of TCAS
14NM
if I’m high density airspace range can be lowered to 5nm
How many aircraft can TCAS resolve
30 aircraft
When does TCAS inhibit it’s warnings
Totally if GPWS or windshear warning is active
“Increase descent” RA it below 1500feet rad alt
“Descend” RA below 1100feet rad alt
All TCAS aural annunciations below 1000ft
TAs will indicate below this though
Where is TCAS mode control and what is it set to for normal ops
Found on transponder panel
Usually operated in TA/RA
When might TCAS be switched to TA only
Parallel runway
Engine failure
How should a crew respond to TA TCAS
Look for aircraft
How should crew respond to TCAS RA
Disengage autopilot
Quickly but smoothly follow RA instructions
Inform atc as soon As practical after completion
TCAS takes priority over atc
What is TCAS 3
Provides collision avoidance in horizontal and vertical plane
