ACAS and TCAS Flashcards
Define ACAS
Airborne Collision Avoidance System (ACAS)
An system using SSR and operates independently of ground equipment to provide advice to the pilots on potential conflicts
On which aircraft does ACAS provide conflict advice?
Aircraft equipped with SSR transponders.
No transponder, No TCAS.
Which aircraft must have ACAS?
Turbine powered aeroplanes with a MCTOM of 5700kg or more, or 19 seats or more
Which is the only equipment available which satisfies ACAS?
TCAS II
Which is the only transponder which communicates and agrees a course of action?
Mode S
What are the key components of TCAS?
Antennae
TCAS Processor
Transponder Control Panel
VSI Display
Voice Warning System “Traffic Traffic”
If no Mode C data is being transmitted, can TCAS detect a threaT?
No, TCAS cannot determine whether this is a threat as no altitude data is being transmitted
What is TCAS Proximity Traffic?
Any target within 6nm and within 1200ft
Describe a TA
Traffic Advisory. When traffic is given a “threat” status
TAs are issued 20-48 seconds before Closest Point of Approach (CPA)
Describe an RA
Resolution Advisory. The beginning of the conflict resolution process.
RAs are issued up to 35 seconds before CPA
Should pilots take avoiding action on the basis of a TA?
No
Should pilots take avoiding action on the basis of an RA?
Yes, pilots shall respond immediately
What are some limitations of TCAS?
“Increase Descent” is inhibited below 1450ft AGL
A Descend RA is inhibited below 1100ft AGL
All RAs inhibited below 1000ft AGL
All Spoken messages inhibited below 500ft AGL
RAs inhibited when some GPWS or windshear warnings are active
What should the ATCO do when notified of an RA?
Do not issue instructions to the aircraft
Do not pass traffic to aircraft conducting RA
During an RA, does the ATCO have responsibility for separation?
No. The ATCOs responsibility for separation ceases
