TCAS/ACAS Flashcards
Which aircraft are mandated to carry and operate ACAS II equipment?
And what a/c are exempt?
MTOM exceeding 5,700kg
More than 19 seats
All Fixed Wing Turbine
Certain civil- registered historical, and military aircraft.
The CAA has endorsed European Policy to conform with what?
ICAO ACAS II SARPS
The only equipment currently available to meet ACAS II requirements is?
TCAS II
Airborne Collision Avoidance System (ACAS): An aircraft system based on________/________/______
Which operates _______/_______/_______/________/________ to provide advice to the pilot on potential_______/________ that are equipped with ______/_______
On SSR transponder signals
Independently of ground based equipment
Conflicting traffic
SSR Transponders
Does TCAS 1 Provide a Resolution Advisory (RA)?
No it doesn’t
What data does TCAS II uses ?
How is this data obtained?
What does this data determine?
Range and altitude.
By interrogating other aircraft transponders to determine the possibility of collision.
Can TCAS II present bearing information?
Yes, TCAS II can present bearing information of a/c intruding into your airspace.
The bearing information on the display is only to?
Assist in visual acquisition of an intruder
When range and altitude of an intruder are computed and a collision risk is predicted TCAS II will declare the intruder a?
And give?
“threat”
Manoeuvre advice in visual and aural form
Avoidance manoeuvres using TCAS II are in the?
Vertical plane only.
Why doesn’t TCAS give bearings to assist in avoiding the “threat”?
Bearing information produced by TCAS II does not process the accuracy necessary for determining horizontal avoidance manoeuvres.
MODE A/C transponders give?
Both Traffic Advisory (TA) and Resolution Advisory (RA)
What happens if the Mode C is not available?
The TCAS is unable to provide either TA or RA. Any manoeuvre may not be in the logical sense.
What does a Mode S transponder do?
Provides both a TA and RA by communicating with each other and “agree” a course of action.
TCAS depends entirely on?
SSR.
No Transponder means?
No TCAS alert
What are the key components of TCAS?
5 things
1) Antenna
2) TCAS processor
3) Transponder Control Panel
4) VSI- Display
5) Voice Warning System
A protected volume of airspace surrounds each ACAS II equipped aircraft.
True or False?
True.
The size of the protected volume of airspace depends upon the?
1) Altitude
2) Speed
3) Heading
Of the aircraft involved in the encounter.
What is the Traffic Advisory (TA) Region if protected volume of airspace?
+/- 850ft
What is the Resolution Advisory (RA) Region if protected volume of airspace?
+/- 600ft
What is the symbol for Non-Altitude Reporting Traffic?
A hollow white diamond
Explain Non-Altitude Reporting Traffic.
TCAS has no way of determining whether this is a threat as No Mode C data is being transmitted.
What is the Non- Threat Traffic Symbol on the display?
A hollow white diamond
Explain Non-Threat Traffic
A common display situation, usually multiple contacts.
How is a Proximity Traffic Symbol displayed?
A fully white diamond.
Explain Proximity traffic.
Any target within 6nm and 1200ft
What is the symbol for Traffic Advisory?
A yellow circle
Explain Traffic Advisory (TA)
Traffic assume threat status
20-48 seconds before closest point of approach (CPA)
Says “traffic traffic”
What are the aircrew actions during a Traffic Advisory?
- Pilots advised not to take avoiding action on the basis of a TA
- May request traffic information from ATC
- Don’t Routinely pass.
What is the symbol for Resolution Advisory (RA)?
A red square
Explain the Resolution Advisory (RA).
Starts the conflict resolution process
Up to 35 seconds before Closest Point Approach (CPA)
“Climb, Climb Now”
What is the aircrew action during a Resolution Action (RA).
- Pilots shall respond immediately( Disengage autopilot and respond within 5 seconds, unless doing so would jeopardise the aircraft)
- But have been instructed to restrict manoeuvres to the minimum necessary to resolve Confliction, advise ATC ASAP and return to original flight path as soon as safe to do so.
Enhanced RA “Increase Descent” is inhibited below?
1450ft AGL
A Descend RA is inhibited below?
1,100ft AGL
All RA’s are inhibited below?
1,000ft AGL.
All spoken messages are inhibited below?
500ft AGL
RA’s are also inhibited when some?
GOWS or Windsheer warnings are active
What is inhibited below 1450ft AGL?
Enhanced RA “increase descent”
What is inhibited below 1,100ft?
A descend RA.
What is inhibited below 1,000ft AGL?
All RAs
What is inhibited below 500ft?
All spoken messages.
Can RAs and TAs occur even though standard separation exists?
Yes.
What are frequent causes of TAs and RAs when standard separation exists?
1) Ground testing of transponders
2) High Vertical Speed- at low level and congested airspace.
When ATC are notified of an RA should they issue instructions to aircraft?
No.
Are ATC still responsible for separation once notified of an RA?
No, their responsibility ceases for the provision of standard separation from affected traffic.
Should controllers pass traffic information during an RA?
No, controllers SHOULDNT routinely pass traffic information to aircraft conducting an RA manoeuvre, or other aircraft affected by such manoeuvres.
When shall the controller resume responsibility for providing separation for all aircraft affected?
(2 things)
1) The controller acknowledges a report from the flight crew that the aircraft has resumed the current clearance.
2) Controller acknowledges a report from flight crew that the aircraft is resuming the current clearance and issues alternative clearance which is acknowledged by the flight crew.
What is the correct RT response after hearing an “(Callsign) TCAS RA”?
“(Callsign) Roger”
What RT is announced in the cockpit once RA response is complete?
Clear of conflict.
When the pilot has reported “(Callsign) clear of conflict (assigned clearance resumes)” over the RT. What is ATCs response?
“(Callsign) ROGER (or alternative instructions)”
During a departure from an ATC Clearance or instruction contradictory to the ACAS RA is received, the flight crew will follow the RA and inform ATC directly by saying?
ATC will respond with?
“(Callsign) Unable, TCAS RA”
“(Callsign) Roger”.
All ACAS RAs are required to be reported under the MOR scheme. True or False?
True.
If there is good reason to believe the appropriate details of the occurrence have already been, or will be, reported under the MOR scheme by someone else then?
There is no need to file a duplicate report.
If someone has already filed an MOR what does this not absolve the controller from filing?
An AIRPROX will be filed where appropriate.
What version is TCAS II on?
Version 7.1
If an Aircraft’s Mode A is only working what will be provided by TCAS?
A TA only
Why action should the ATCO take when the pilot informs them of a TA?
“Call sign Roger”
Don’t provide traffic information unless specifically asked for it. And 100% confident it is the aircraft you think it is(may not always be that one).
Define Airborne Collision Avoidance System(ACAS)
Aircraft system based SSR Transponder Signals which operate independently of ground based equipment to provide advice to the pilot on potential conflicting traffic that are equipped with SSR Transponders.
What is ACAS and what is TCAS?
ACAS: Aircraft system based SSR Transponder Signals which operate independently of ground based equipment to provide advice to the pilot on potential conflicting traffic that are equipped with SSR Transponders.
To comply with ACAS II SARPS
TCAS: the equipment available to meet ACAS II requirements
What are the types of RA available?
Climb
Descend
Enhanced Climb
Enhanced Descent
What are nuisance advisories
RAs and TAs that occur even though standard separation exists
Reverse RA.
TCAS reverse its decisions.
